The Government’s chief medical officer is hopeful that an antibody test to detect if someone has recovered from Covid-19 could be available in the “pretty near future”.

Professor Chris Whitty told a Downing Street briefing that there is currently not a test available that Public Health England (PHE) has enough confidence in.

But Prof Whitty said he hopes a test that gives a “ranging shot” on the number of those who have been infected could be available shortly.

“The problem we have had is we do not yet have a test that is as good as we would want,” he said on Wednesday.

“Many different people are trying to work on an improved test – there are fairly good tests on this at the moment, but there are not very good tests.”

Antibody testing has been seen as crucial in providing an exit pathway from the current lockdown, and also providing data to those developing a vaccine.

Prof Whitty said that he was hoping “we will shortly have tests that are good enough to get at least a ranging shot” of those who have already been infected.

He said: “This is one of the critical bits of information we need to make decisions and I’m hoping – but I’ve been hoping for a while so I don’t want to over-promise on this – that we will shortly have tests that are good enough to get at least a ranging shot as to what proportion of people in different age groups, in different parts of the country, have had this virus.

“But we’re not yet at the point, I think, where we have a test we can say that reliably, but I’m hoping we will be able to do so in the pretty near future.”

The tests, also known as serology tests, look for elevated levels antibodies in blood serum – the body’s first response to an infection.

Levels of the specific antibodies used to fight the virus usually peak about 21 days after the patient has become infected.

Many tests being developed are pin prick blood tests similar to widely-used instant HIV tests and measure for raised levels of the antibodies the body uses to fight the virus.

Hopes that the tests could be a route for the UK to exit the lockdown were dealt a blow last week when World Health Organisation (WHO) epidemiologists warned there is no proof those who have been infected cannot be infected again.