his escape has triggered alerts at ports and borders around with the uk — with reports of delays because of the increased securtiy checks. prisoner escapes are unusual — there've been just five since 2017. our home affairs correspondent, daniel sandford, is outside scotland yard. kate is at heathrow and chris mason joins us from westminster. daniel, what happened?— joins us from westminster. daniel, what happened? daniel khalife was bein: held what happened? daniel khalife was being held at _ what happened? daniel khalife was being held at hmp _ what happened? daniel khalife was being held at hmp wandsworth - what happened? daniel khalife wasi being held at hmp wandsworth and what happened? daniel khalife was - being held at hmp wandsworth and had been there for a few months after having been charged injanuary with terrorism offences and also offences against the official secrets act. he is alleged to be working for a hostile state. he was working in the kitchen at hmp wandsworth this morning wearing the uniform of a cook this morning in red and white checked trousers and white t—shirt. what people think happened is that he simply clung onto the bottom of a food delivery van and was driven out of hmp wandsworth. that seems to have been the way he made his escape. obviously investigations are going on as to how that happened but the working theory is he was literally driven out of the prison strapped to the underside of a food delivery van. in the last hour i have been speaking to commander dominic murphy of counterterrorism command and i asked him how hard police are working to find daniel khalife. , . , ., , , , police are working to find daniel khalife. , . , ., ,, , . ., khalife. this rarely happens. we are su ”ortin khalife. this rarely happens. we are suworting our _ khalife. this rarely happens. we are supporting our colleagues _ khalife. this rarely happens. we are supporting our colleagues in - khalife. this rarely happens. we are supporting our colleagues in the - supporting our colleagues in the prison— supporting our colleagues in the prison service and across government and other_ prison service and across government and other agencies in the country who are — and other agencies in the country who are involved in the criminal justice — who are involved in the criminal justice system. for us the focus is on locating — justice system. for us the focus is on locating daniel khalife, bringing him back— on locating daniel khalife, bringing him back to custody, and making sure he stands _ him back to custody, and making sure he stands trial and the public are an important part of that process. commander murphy stressed that he didn't think daniel khalife was a particular risk to the public. the charges weren't about using a knife or bombs or something to try and harm people they were more related to working for a hostile state. but it is incredibly urgent this prisoner be brought back to prison and because of the nature of the charges there is a concern that he might try to escape the country and thatis might try to escape the country and that is why special alerts are taking place at ports and airports. though police think it is more likely that he is probably still in london. . ~ likely that he is probably still in london. ., ~ , ., likely that he is probably still in london. ., ~ ., , ., likely that he is probably still in london. ., ., ., ., london. thank you. cady at heathrow, it is havin: london. thank you. cady at heathrow, it is having an — london. thank you. cady at heathrow, it is having an impact _ london. thank you. cady at heathrow, it is having an impact on _ london. thank you. cady at heathrow, it is having an impact on ports - london. thank you. cady at heathrow, it is having an impact on ports and - it is having an impact on ports and airports, though, isn't it? == airports, though, isn't it? -- katie. that's _ airports, though, isn't it? » katie. that's right. the met police said an alert was issued by the counterterrorism command to the relevant uk police and law enforcement agencies, including those at ports and the border. as a result, extra checks have been taking place as the search continues. that includes at heathrow airport, britain's biggest airport behind me, and at gatwick, and also the port of dover. some airports, including glasgow and manchester, we've had reports that that caused longer than usual queueing but that situation does seem to have improved as the afternoon has gone on and at the port of dover, that is another place where there have been delays as a result of these additional security checks.— as a result of these additional security checks. thanks. let's talk to chris mason _ security checks. thanks. let's talk to chris mason in _ security checks. thanks. let's talk to chris mason in westminster. i security checks. thanks. let's talk i to chris mason in westminster. this is very rare, particularly for terror suspects, what is the government saying? the justice secretary described _ government saying? the justice secretary described an - government saying? the justice secretary described an urgent . government saying? the justice i secretary described an urgent call with the governor of wandsworth prison. one of the senior figures from the prison service. it will not surprise you that one of the items on the agenda on that call was a seeking of reassurance from the government around security from now on at wandsworth prison. westminster tonight is just absorbing this news. speaking to some people privately, questions are already being asked about whether it was why is this man was at wandsworth prison rather than, perhaps, belmarsh prison in south—east london which is seen to have higher security. lots of questions being asked every moment. again, speaking to other people, when you are a cabinet minister you are only one day away from disaster and tonight we have a situation where the ministry ofjustice and the metropolitan police and other police forces around the uk, as well as, no doubt, the intelligence services, are trying to find the most wanted man in britain. and then asked the question, how on earth did circumstances arise that he managed to escape in the first place. thank ou, to escape in the first place. thank you. chris. _ scientists in israel say they have grown an entity that closely resembles an early human embryo — without using sperm, eggs or a womb. it's called an embryo model and the team at the weizmann institute say it looks like a textbook example of a real 14—day old embryo and could revolutionise our understanding of the earliest moments of our lives. our health and science correspondent james gallagher is here. this is a field that has been progressing rapidly, and has now reached a significant moment. take a second to think how remarkable it is that our lives start as this — a single egg fertilised by a sperm. the first steps on the journey from this to us are poorly understood and researching embryos is legally, ethically and technically fraught. this is where embryo models come in, and this is how it's done. there are no sperm or eggs involved. instead scientists start with human stem cells. these have the potential to become any type of tissue in our body. these are then transformed into the four types of cell you'd find in an embryo that was just one week—old. 120 of them are mixed together, and you can see they start off as a jumble, but as they grow this happens. they start to organise themselves, mimicking what a real embryo would look like 14 days after fertilisation. and we can have a look at one. now this might appear confusing, but we can spot some things in here. the purple cells on the outside are the ones that would grow to form the placenta. and as we look inside, the yellow cells would create the yolk sac. and the blue cells would form in a real embryo and the blue cells would form in a real embryo a human being. now of course this isn't a real embryo, it's not possible to put this in a womb and make a baby. but it is similar. it even released hormones that made a pregnancy test turn positive in the lab. and that's what's exciting the research team in israel. yes, this does look like textbook and all the structures are there and it looks really, really good. this is a stem cell derived entity that has all the subtypes, all the compartments and in the right orientation, which hasn't been done before. for those struggling to start a family this research may help. it could lead to new ways of tackling infertility or improving ivf. and that's because these embryo models allow scientists to perform research that would be impossible on real embryos. to understand the crucial early moments of our development when miscarriage and birth defects often arise. they are embryo models. they are very close to them. should you regulate them in the same way as a normal embryo or can you be more relaxed about how they are treated because they are not actually normal embryos? you could not implant one of these into a woman because that would be illegal and they probably wouldn't work anyway. this would be illegal and they probably wouldn't work anyway.— would be illegal and they probably wouldn't work anyway. this field of research is — wouldn't work anyway. this field of research is advancing _ wouldn't work anyway. this field of research is advancing rapidly - wouldn't work anyway. this field of research is advancing rapidly and i wouldn't work anyway. this field of research is advancing rapidly and itj research is advancing rapidly and it has left regulators playing catch up. james gallagher there. the government has published the list of schools in england affected by so—called crumbly concrete. 147 schools have been found to have raac — which is reinforced autoclaved aerated concrete — that is prone to collapse. 19 in england have had to delay the start of terms because of the concrete crisis. and pupils at some 2a schools will have to get some form of remote learning. the government says the list is only up to date to the 30th august, so the actual number is likely to be higher. ere's our education editor, branwen jeffreys. this secondary school has been propping up raac concrete panels for months and they had been told the risk was low until a call last week saying the advice had changed. this is the pe saying the advice had changed. ti 3 is the pe department. as you can see there is plenty of mitigation in place to support the raac concrete ceiling we have here. this was installed in the summer term last year. installed in the summer term last ear. , �* , installed in the summer term last ear. ,�* , , year. it isn'tjust the pe block. year. it isn't “ust the pe block. some of year. it isn'tjust the pe block. some of the science _ year. it isn'tjust the pe block. - some of the science classrooms are affected as well. it some of the science classrooms are affected as well.— affected as well. it is very difficult to _ affected as well. it is very difficult to be optimistic i affected as well. it is very - difficult to be optimistic about opening this part of the school at any time if at all. find opening this part of the school at any time if at all.— any time if at all. and they had just redecorated _ any time if at all. and they had just redecorated the canteen. l any time if at all. and they had - just redecorated the canteen. we are auoin to just redecorated the canteen. we are going to use — just redecorated the canteen. we are going to use the _ just redecorated the canteen. we are going to use the gymnasium - just redecorated the canteen. we are going to use the gymnasium and - going to use the gymnasium and the marquee forfacilities. marquee for facilities. disappointing because this has been recently refurbished. but it isn't usable. ,. , usable. the school was built in 1942. usable. the school was built in 1942- last _ usable. the school was built in 1942. last year _ usable. the school was built in 1942. last year their _ usable. the school was built in 1942. last year their bid - usable. the school was built in 1942. last year their bid to - usable. the school was built in - 1942. last year their bid to rebuild was turned down. now some children will learn online. it could take two to three months to get temporary classrooms in place.— to three months to get temporary classrooms in place. frustration by all accounts- _ classrooms in place. frustration by all accounts. we _ classrooms in place. frustration by all accounts. we didn't _ classrooms in place. frustration by all accounts. we didn't know- classrooms in place. frustration by all accounts. we didn't know about it. we didn't feel there was a risk. we are worried about what this does to families. , ., , .,. to families. these teenagers face gcse exams _ to families. these teenagers face gcse exams next _ to families. these teenagers face gcse exams next year. _ to families. these teenagers face gcse exams next year. we - to families. these teenagers face gcse exams next year. we are i to families. these teenagers face . gcse exams next year. we are being told that we — gcse exams next year. we are being told that we are _ gcse exams next year. we are being told that we are going _ gcse exams next year. we are being told that we are going back - gcse exams next year. we are being told that we are going back on - told that we are going back on monday but it could be a mixture of online learning. it would be the case of when we are going back full—time. if case of when we are going back full-time— full-time. if you are stuck you can'tjust _ full-time. if you are stuck you can't just ask _ full-time. if you are stuck you can'tjust ask the _ full-time. if you are stuck you can't just ask the teacher - full-time. if you are stuck you can't just ask the teacher in i full-time. if you are stuck you i can'tjust ask the teacher in front can't just ask the teacher in front of you _ can't just ask the teacher in front of you so— can't just ask the teacher in front of you so it — can't just ask the teacher in front of you so it is a lot harder to understand the work. in of you so it is a lot harder to understand the work. in 2010 this london school _ understand the work. in 2010 this london school had _ understand the work. in 2010 this london school had funding - understand the work. in 2010 this london school had funding for- london school had funding for rebuilding pooled. they now have raac concrete. leading to a row in parliament about whether cuts are to blame. —— the rebuilding pulled. this is as a result of sticking plaster politics and botched jobs. the sort of thing you expect from cowboy builders saying that everyone else is wrong, everyone else is to blame, protesting they've done a really good job, even if the ceiling falls in. the difference, mr speaker, is that in this case the cowboys are running the country! cheering the prime minister defended their record. , , , ~ ., record. this is exactly the kind of olitical record. this is exactly the kind of political opportunism _ record. this is exactly the kind of political opportunism we - record. this is exactly the kind of political opportunism we have i political opportunism we have come... cheering exactly the kind of opportunism we have come to expect from him over there. �* ., ., �*, ., . there. before today he's never once raised this issue _ there. before today he's never once raised this issue with _ there. before today he's never once raised this issue with me _ there. before today he's never once raised this issue with me across i raised this issue with me across this dispatch box. he talks about 13 years, well, let's see what happened, a third of schools were good are outstanding when we first came in, now it is 90%. this good are outstanding when we first came in, now it is 90%.— came in, now it is 90%. this week the education _ came in, now it is 90%. this week the education secretary, - came in, now it is 90%. this week the education secretary, who i came in, now it is 90%. this week the education secretary, who has| the education secretary, who has told some schools to get off their backsides, but the head teachers say the list of schools is muddled. ianthem the list of schools is muddled. when ou have a the list of schools is muddled. when you have a government _ the list of schools is muddled. when you have a government that - the list of schools is muddled. when you have a government that gets the list of schools is muddled. emery you have a government that gets into this shambles by not responding to all of the information it had early on. and when you are in the chaos you are in cannot even get the paperwork right as to who has and hasn't responded it cannot fill you with confidence, can it?— with confidence, can it? while schools are — with confidence, can it? while schools are still _ with confidence, can it? while schools are still working i with confidence, can it? while schools are still working out i with confidence, can it? while i schools are still working out what to do the number affected is likely to do the number affected is likely to go up. the research team that highlighted the problems posed by raac has said that potentially tens of thousands of government and privately owned buildings may also be at risk. our science correspondent, pallab ghosh has been to their lab to find out what they discovered that made the government suddenly reassess the dangers. welcome to the concrete lab. scientists at loughborough university are britain's leading experts on reinforced aerated autoclaved concrete — or raac for short. although raac has been used for decades, there's been next to no research into what happens to it when it ages. and that's exactly what the team here have been looking into for the past two years and it's their results that have shown that the risks are greater than previously thought. so, we put it here. this test shows that the holes in raac make it lighter than normal concrete, but it soaks moisture like a sponge. when put under pressure, the wet sample on the left breaks apart earlier than the dry one. how did the wet one do compared to the dry one? 25% wea ker. it's very concentrated... and they've also found that there's damage inside, around the steel rods that are supposed to strengthen it. are these cracks here? we might have cracks, might have defects. and this is potentially a reason for concern as well because the material, the steel and the concrete need to work together. under the microscope, you can see the damage that's otherwise invisible. this is concerning because without a warning a brittle failure, and a catastrophic one can happen with grave consequences. so there was a greater risk of sudden failure? yes. the new research shows that many more government buildings are at risk, such as courthouses and the government is rebuilding seven new hospitals because of problems with raac. but the problems don't end there. we have the challenge that the private sector represents, which is a huge one. so the private sector, we're talking about office blocks all across the country? it could be, if they were built between �*50s and �*80s. we need to look carefully. so we're talking about tens of thousands of buildings all the country? potentially, yes. the team is advising the government to send surveyors to assess the affected buildings. the hope is that most won't have raac that's degraded to a dangerous level, but they will have to be inspected regularly. others may need areas reinforced and a small number may need to be rebuilt. pallab ghosh, bbc news, loughborough. our top story this evening. a man hunt is launched for a 21—year—old terror suspect who has escaped from london's wandsworth prison. and still to come... with temperatures across southern england