Lead to contamination. The government has spent over a billion pounds setting up a network of testing labs, including this one in Milton Keynes. Hi, folks, im here at the Milton Keynes mega lab where theyre doing the most phenomenal amount of testing. But i find frustrated staff losing faith in the system. Every tube is a person. You have to think that way. And probably quite a scared person or worried person. As we begin to return to normal life, can we trust testing to help keep us safe . You just cannot run a service like this. Whos in charge here . Im so motivated to go in and really find out whats happening there. Its so important to get testing right because essentially, thats our first line of defence with covid. Testing is a cornerstone of the governments fight against coronavirus. The most reliable tests are called pcr. Thousands of samples every day are sent here, to one of the uks biggest labs, Milton Keynes. Panorama has been told by sources about poor practices at the lab.