something they feel that they need. where migrants are packed into flimsy, inflatable boats and sent off into the sea. record numbers of migrants are now reaching british shores this way, and the smugglers are always one step ahead. so who's winning the battle in the channel? we're out on patrol to ask why two of the world's richest and most powerful countries can't stop migrants crossing 20 miles of sea. it's four o'clock in the morning, and we're out on patrol with general frantz tavart and his team of gendarmes. he runs a constant patrol of a0 active gendarmes and 90 reservists, paid for by the uk. together with the police, they patrol almost 90 miles of coastline around calais. this area is known as a goldmine for migrants, but tonight, the beaches are empty. it's a sign, says general tavart, that the french patrols are working. the smugglers may be moving away from calais, but the number of migrants reaching britain from northern france has more than doubled this year. geography is on the smugglers�* side — how do you police a long, snaking coastline, covered with trees, dunes, and hundreds of bunkers left over from world war ii? this is the kind of terrain that the patrols here have to police every night. the sand is so fine your boots sink into it. sometimes there isn't even the moon for light. we check one popular hiding place, but the migrants have gone. they often leave in a hurry. clothes, nappies, even lifejackets — these are the things you leave behind. as dawn approaches, general tavart gets a call — something is happened further down the coast. police have caught a group of migrants in inflatable boat. by the time they reach them, the boat is in the water. this, smugglers tell their clients, is when you're safe from the french police. but tonight, the gendarmes wade into the sea and begin to pull the boat back. it's packed with people. it doesn't take long for one man to realise the game is up andjump out. he helps drag the boat back to shore. everyone on board is likely to have paid between one and 3000 euros for the passage. it's late in the season, when fares are cheaper, and poorer migrants tend to travel. not everyone on board seems to have a life jacket. 0ne kicks at the water as he goes. the officer filming says he can hear a baby crying. seconds later, the baby appears, in a bobble hat to dull the cold of the channel crossing. the boat, thought to have been custom—made, is confiscated. the migrants themselves walk away, back to their camps, to try again. that night, french patrols stopped almost 200 migrants from crossing the channel, but three times as many people did make it to the uk. so what would it take to stop them? we've come to the eurotunnel site at coquelles to find out. and again you can see there's another layer of fencing here. this is the third skin of preventative fencing. calais has been drawing migrants for decades, but until 2018, almost none of them tried to cross the channel in small boats. instead, they used to jump on trucks bound for the ferry port, or come here, to the channel tunnel entrance, to hide on trains bound for the uk. hundreds of migrants used to try and break into the tunnel each day. they don't anymore. the problem's not fixed. the problem's contained as far as our terminal is concerned. and that's been done by basically building a — a perimeterfence around the terminal and adding surveillance cameras, motion detectors, infrared, using drones. we've now got over 600 different video surveillance points around the site, and 37km of fencing — high—security fencing around the site, and regular security patrols, and we're working in cooperation with the authorities — police on both sides of the channel. so there's a whole structure, both physical and intelligence—based, that operates to protect this small site. it costs the uk government £65 million to secure the eurotunnel site — that's about £26 million per square mile. it worked. migrants and smugglers shifted to small boats. but doing the same along 100 miles of coastline is virtually impossible. forested dunes complicate video surveillance, and you can't put a fence around france. david, a migrant himself, has sometimes worked for the people smugglers here. he had hoped to earn a place on one of their boats, but says it never happened. "they're greedy," he says, "and there are plenty of passengers who will pay." he's brought me here to show me one of their hiding places. this is where they bring people before they put them in the boat — an old makeshift shelter. above is a field of cows. and david isjust going to show me inside where they store the equipment. it's pretty dark in here. scattered inside is the debris left by previous groups. and, hidden in the floor, undera rock, a dinghy, wrapped in plastic, and ready to inflate. smugglers now often stash the boats separate from their passengers, to stop them being taken if there's a raid by the police. david shows me the route down to the beach. "the smugglers would get wind of a police patrol up to two hours before it reached them," he says. this year, under growing pressure, the uk announced funding to double the number of patrols on french beaches, and increased surveillance. it's spent almost £90 million on securing this coastline in the past few years. but is the investment having any impact? with more than 4000 migrants reaching british shores last month alone, newspaper headlines are screaming their disapproval. dan 0'mahoney is the man appointed by the government to stop it. we can't build a fence around 200km of french beaches, but what we can do is invest in the long—term in really advanced surveillance technology that allows the french boots on the ground to get to the right place at the right time. but it doesn't work — it doesn't work because we've spoken to migrants who say look, they see the french patrols coming two hours before they get there. isn't it time to be straight with the public and say "look, we cannot police the channel this way"? well look, we've been absolutely clear that the ideal outcome is that the migrants and the criminals are stopped before they get anywhere near a beach in france. but that's not happening frequently enough to break the business model. we're investing in that last stage of the journey in france, on the beaches and around the beaches, with the technology, with french law enforcement officers, and it's not working as well as we want it to. we need to get to the stage where it's more likely than not that if you attempt to cross the channel, you will be stopped. french patrols are now stopping more than half the number of boats from crossing, but the number of attempts has mushroomed this year, partly thanks to covid restrictions drying up other transport routes. in the migrant camps, people smuggling networks seem to be flourishing, despite 65 criminal convictions related to small boat crossings and a newjoint intelligence centre set up here last year. hamid — that's not his real name — is one of many new arrivals from afghanistan. he was a soldier in the afghan national army and says he trained with the british forces. we voiced over his words to protect them. if i stayed, the taliban would kill me — and not only me, but my whole family. i went to the embassy and asked them to help me. i said "i worked with you". if you worked just one day for the army, the taliban will kill you — one day — and i'm national army. i worked many years with the americans, with the british, but now i'm scared. what did the british embassy say to you? he said "you must wait for an e—mail. "i will send you an e—mail and then you must come to the intercontinental hotel — the big hotel." i waited, but he did not send it to me. i went to the airport many times but they did not help me. i went back to the embassy but he still didn't help me. then i came by myself to istanbul, then hungary, then paris. i paid 3000 euros from kabul to istanbul. you paid a smuggler? yes, i paid. he took my passport and after three days, he brought my passport, visa, ticket — everything. most of the people i've met here have made contact with a people smuggler within a couple of weeks. some even made it to the uk in that time. hamid had been here a week when we met. he'd just started looking. three days after our interview, i get a message on my phone. hi, lucy. last night i tried by boat — 75 people from dunkirk — but before we put the boat in the sea, the police came and stopped me. when i speak to him, hamid tells me that the police told the migrants to go back to their camps and try again. he also tells me the smugglers had heard he was talking to the bbc and had threatened him, telling him to stop. general tavart says his men just don't have the resources to detain dozens of migrants. bigger boats with more passengers are one of the ways smugglers have adapted, and it's creating fresh problems for police. have there been times when you have had to let them go because you... with smugglers now using internal waterways to transport boats to the coast, pressure on all sides is growing. over the summer, the home secretary priti patel threatened to withhold more than £50 million of funding for the mission this year, unless france stopped more boats. while on patrol with us, general tavart issued a threat of his own. shared costs are one thing, shared interests and priorities another. france received more than 150,000 asylum claims in 2019. the uk, around 35,000. with relations strained after brexit, how far will france go to stop a small percentage of its migrants who want to leave for the uk? what has happened over the last ten years, every single time there's an issue, we say "ok, we need five more million for this, 5 million for that," but we are not actually really trying to solve the problem, which means actually working together more closely. john—paul mulot, currently working for france's centre—right presidential candidates, used to be the cross—channel envoy for france's northern region in the run—up to brexit. he spent years studying border arrangements there and talking to those on both sides. if you work together, it has to be really a joint force on the ground where in the army, at the moment, we still have, due to the bilateral treaty, we've got a french colonel running, you know, a british, you know, regiment and we've got a british, you know, commander—in—chief somewhere working with the french — the french military. why is it that we cannot have that at the border and have a joint border force, you know, and that would actually tackle illegal migration? unlike at ferry ports, migrants found by british patrols in british waters cannot be returned to france. with smugglers selling their clients unrealistic dreams of life in the uk, reception facilities there are now vastly overstretched. 0njoint patrols, you know, we have offered to the french many times for us to deploy british officers onto the beaches. it's not something they feel that they need or would find helpful, but the offer is always there. we would love to do joint patrols at sea as well. the french have a very strong view about sovereignty and therefore, it's not an avenue they want to explore at the moment. sovereignty is a loaded issue after brexit. we met france's interior minister last weekend as he visited security forces along the coast. after months of criticism that his patrols are letting too many migrants across the channel, he told us that france had not yet received a penny of the £54 million promised by priti patel three months ago. the uk government says you're just not doing enough, you're not really trying. however good the cooperation between forces on the ground, political relations have been strained — and notjust by migration. rows over post—brexit fishing licenses and a secret submarine deal in the pacific have stretched diplomatic niceties to breaking point. general tavart can issue orders to his patrols on the ground but it's politicians in paris who issue orders to him. as dawn approaches, we join the unit on their new patrols along france's final frontier. it's their last chance to intercept migrant boats and take them back to france. but the game of cat and mouse is much riskier than on land and unless a migrant boat is in distress, french forces will escort them into british waters, rather than intervene. the uk now says if france won't intercept boats and turn them back, british border police might — if it's safe to do so. over the past two years, at least 14 people are known to have died trying to cross this slim patch of water. constrained by humanitarian risks and political alliances, maritime borders like this are difficult to police — smugglers know that as well as governments do. the battle in the channel today is a story of migrants slipping between the sovereignties of two great nations. a story of david and goliath, where vulnerability brings its own protection and sovereignty sets the limits of national power. good evening. changeable but very mild. it's a good the jet stream for us. some big patterns here. big peaks and troughs, of peak of her green in there and peeking again of western parts of europe and we can see the syndication and through the northern and southern lines, cooler air, warmer air being pushed up ahead in the back to cooler air again and lots of low pressure is forming in the north atlantic as a result of these temperature contrasts as well in towards the end of the week, it's going to turn a little bit quarter. to summarise, what the next few days are going to look like his bouts of heavy rain, particularly across the precious approaching. some big patterns here, big peaks and troughs, you can see a peak going over greenland there, trough in the north atlantic, then peaking again across western parts of europe. and when we see this sort of pattern, that gives us an indication there'll be a lot of mixing in the atmosphere between the northern and southern climes — so pulses of cooler air pushed up ahead, then back to cooler air again. lots of low pressures forming in the north atlantic as a result of these temperature contrasts as well, and towards the end of the week it looks like it will turn a little bit colder. so let's summarise what the next few days will look like — bouts of heavy rain particularly across western areas with low pressures approaching, that also means gale force winds, but we will also see a lot of mild air, very mild air, in fact, pressures approaching, that also means gale force winds, but we will also see a lot of mild air, very mild air, in fact, streaming in from the azores. now this is the weather map for monday — and a big low—pressure with winds blowing around it like so, that low—pressure is also scooping up that mild air from the south. see, the mild south—westerlies here. so outbreaks of rain during the course of monday, moving across the uk and, despite the cloud and the rain with those warm south—westerlies, temperatures will get up to around 16—18 celsius. and it stays cloudy with these mild south—westerly use into tuesday, as well — in fact, we are expecting another weather front to approach us early on tuesday morning, and that spells another bout of heavy rain across the west and the southwest. look at the morning on tuesday — 15 celsius, that's exceedingly mild for this time of year. now here's a weather front that's moving across the uk during the course of tuesday and, in this sort of situation, most of the rain usually falls around parts of wales, the northwest of england, as well. there could be some problems with local flooding. that rain will be quite persistent and, when we have these mild south—westerly is, it's often the case that there is a lot of moisture in the atmosphere, and all that rain falls, then we have some problems at times. but in the southeast of the country on tuesday, temperatures could even get up to 20—21 celsius if the clouds break — it really all depends on the cloud cover. now here's the forecast into wednesday — so an area of rain across the uk, it's not raining everywhere — in fact, look at that, northeastern scotland may actually end up being quite bright if not sunny, and even for a time we will see some sunshine developing across parts of the midlands and maybe the southeast, as well. and again, up to around 18 celsius, but we are starting to see those temperatures drop across northern areas. midweek — and that's because the wind direction�*s changing. remember all that mixing in the atmosphere i showed you early on? so here comes the northerly winds just ahead of it in the south, we've got that westerly to south—westerly and possibly gale force winds with the mild air and outbreaks of rain in the south. so 1a in london, but a lot colder there, around 8— nine in scotland. no it'll calm down briefly on monday, we've got low pressures — one across scandinavia, one in the atlantic — but this ridge of high pressure briefly builds,