After several days of intense scrutiny over failures in testing, the Health Secretary said he was setting out a new "five-pillar" strategy on the issue and that the UK would carry out 100,000 tests per day by the end of April.
There will be a combination of tests for live cases of Covid-19 and antibody tests to determine whether someone has previously been infected, he said. And when the antibody tests are available the government would look at the possibility of issuing immunity certificates, he added.
"We are looking at an immunity certificate - how people who have had the disease, have got the antibodies and therefore have the immunity, can show that and so get back, as much as possible, to normal life," Mr Hancock said.
The Prime Minister's spokesman said this had been discussed in other countries and the UK was watching what happened closely.