Boris Johnson ignored expert evidence on preventing a pandemic when he failed to crack down early enough on coronavirus, a former chief scientific adviser says.

In a devastating attack, David King also warned that “underfunding” of the NHS by the Tories had undermined efforts to fight back against the outbreak and save lives.

Highlighting planning he did more than a decade ago, Sir David said: “We did all the work that needed to be done – we did prepare the ground.”

The prime minister delayed introducing the near-lockdown for crucial weeks, even as other countries imposed tough restrictions as the crisis unfolded in China.

But Sir David said: “We did, for example, a calculation to show that – wherever this virus appeared in world – within 3 to 6 months it would be in every country of the world.

“Well, we have just seen that play out. This began in China in December – it is now virtually everywhere.”

Speaking to Sky News, the chief scientific adviser between 2000 and 2008 added: “We know that what we should have done, early on, is take all sorts of precautionary measures to see that the virus did not get to the level it is now in this country, once we had seen what was happening in China.

“But the response has been slow and, I think, because our National Health Service has suffered from underfunding from that 2010 period.”

The comments come amid the first signs of public concern about the government’s handling of the crisis, despite the prime minister’s sky-high poll ratings.

According to the survey by Ipsos MORI, 56 per cent believe the social distancing measures were imposed too late, while just four per cent believed they were brought in too soon.

It came as the latest official figures showed that 2,921 people have died after contracting the virus in the UK while over 33,000 have tested positive.

It was only 10 days ago that Mr Johnson said people should only leave their homes to buy groceries, to exercise once a day or to travel to work if absolutely necessary.

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Three days earlier, he ordered pubs, bars, restaurants, theatres, cafes and leisure centres to close – having earlier stepped back from doing so.

Throughout, ministers have insisted they have followed the advice of their scientists, but that disguises the U-turn when the strategy of aiming for so-called ‘herd immunity’ in the population was abandoned.

The apparent plan to allow the disease to spread among healthier people is blamed for the delays in ordering sufficient testing.

Critics say the government ignored public health experts and doctors in favour of behavioural scientists and mathematical modellers.