• Video report by ITV News Political Correspondent Libby Wiener

Britain is testing its frontline NHS staff "nowhere near enough", Public Health England's medical director has said - but he insisted capabilities are "ramping up as we speak".

Speaking to ITV News, Paul Cosford acknowledged the poor testing ratio, with just 2,000 NHS staff members being tested - as of yesterday - compared to the 1.2 million people working for the health service.

He said the difficulty in ramping up capabilities had been caused by a range of issues, such as accuracy of tests and the need for "building a whole new and very large capacity very quickly".

"You’ll have heard the number 2,000 from yesterday - that’s nowhere near enough," he said.

"The importance of testing is to get it right and of course this was a test that didn’t exist at the beginning of the year because we didn’t know about the coronavirus," he added.

"We’ve had to design that test, to build that test to make sure that we know how to do it accurately.

"Otherwise, the test is of no use at all."

The Prime Minister’s spokesman said that in all, 10,412 coronavirus tests were carried out across the UK in NHS and Public Health England laboratories on Tuesday.

  • ITV News Political Correspondent Paul Brand explains issues around testing:

“We acknowledge that more needs to be done in relation to testing.

"We need to be testing more people and we need to be making progress very quickly,” he said.

The spokesman said that work was ongoing with nine potential suppliers on developing an antibody test which would show whether people have had the virus, but he said it was essential they were accurate.

“We are working as quickly as we can on that and as soon as a test is approved then we will announce it publicly,” he said.

He said the Government had previously been offered tests which had not met the required levels of accuracy “and therefore would not have been safe to use”.

Mr Cosford claimed scaling up capacity was already going on, with five drive-through testing facilities already available for NHS staff and "another four to come on stream this week".

Another issue in scaling up was caused by the health service needing to use "large numbers of laboratories that are not normally part of the core NHS system".

"It just takes time to get that right and unfortunately that’s taking more time than we had either hoped or intended," he added.

While he admitted "we’ve got to get testing right", he said "we’ve also got to absolutely carry on with social distancing".

"If we get social distancing right then hopefully we will see a plateau in the number of cases in a small number of weeks and then the numbers will start to come down and then we’ll be able to lift some of the measures in due course."

In a video message on Wednesday evening, the prime minister said he was committed to "massively ramp up" testing as it would allow Britain to “unlock the coronavirus puzzle” and "defeat it in the end”.

Mr Johnson was already facing criticism for the UK's initial relaxed attitude to testing, after it was said tests would only be carried out on those with symptoms, but with his latest comments he's heaped up expectation to improve Britain's capabilities.

Labour says the UK is "not testing enough people compared with other countries."

Shadow Attorney General Shami Chakrabarti said, "in particular compared with the countries that are doing best at minimising fatalities".

Officials are “working hard” to address the issue of a lack of tests and to resolve a shortage of testing materials for coronavirus, the chief executive of the Health Service Executive said.

Paul Reid appealed to the public to “bear with us” as the HSE tries to address the worldwide issue.

Mr Reid claimed the issue around testing was a "worldwide shortage" of reagents which are used in the testing process.

In a Tweet he wrote: “In a short time we have scaled up on, testing centres, testing kits, contact tracers, nbr of Labs, hospital beds, ICU, ventilators, PPE, staff.

A drive through coronavirus testing site in a car park at Chessington World of Adventures in Greater London, as the UK continues in lockdown to help curb the spread of the coronavirus. Credit: PA

“Our current major issue is ‘reagents’ for labs.

“A worldwide shortage. We are working hard to fix this. Bear with us.”

Meanwhile, new testing devices that can diagnose Covid-19 "in less than 90 minutes are being deployed" at a hospital in Cambridge.

The portable machines, called Samba II, have been developed by a University of Cambridge spin-off company called Diagnostics for the Real World, and 10 are being used at Addenbrooke’s Hospital this week.

The researchers said their tests have been validated by Public Health England and the devices are expected to be launched in hospitals across the country.

But many have questioned how - with the reagents problem being global - countries such as Germany have been able to test so many more people than the UK.

Figures released yesterday showed Germany had carried out 918,460 coronavirus tests in total.

On Wednesday evening's daily coronavirus press conference, Business Secretary Alok Sharma just 152,979 people in the UK have now been tested.

While Germany is carrying out around 50,000 a day, Mr Sharma said the UK's capacity was at 10,000 tests a day.

He said it was the government's priority to boost that figure and Professor Yvonne Doyle, who was alongside him, said the aim was 25,000 a day.

She said: “In terms of mass testing, the testing strategy is to increase the amount of testing done not just in healthcare workers but in the population.

“The rate-limiting step there is not us, it is really whether the tests are valid and then to get that out and about, and aided by technology.”

Until now, the focus has been on testing patients in hospital to see if they have coronavirus, with NHS trusts told earlier in the week they should use up to 15% of any spare testing capacity for NHS staff.

That cap has now been scrapped and the priority is to test frontline staff so anyone self-isolating can get back to work if possible.

Prime Minister Johnson said: "What we need to do is massively ramp up not just tests, so you can know whether you’ve had the disease in the past – the so-called antibody test – because that will enable you to go to work in the confidence you cannot be infected or infectious.

“Second, people need to know they haven’t got it rather than isolating themselves at home for no reason – that’s very very important above all for our NHS staff.

“It’s crucial people who do have the disease are able to be tested positive and to take the necessary steps to isolate at home in the way that I am doing and many many others are doing.”