Britain’s Covid-19 death toll passed 100,000 on Tuesday, more than twice the number of civilians killed in the Blitz, with Boris Johnson declaring: “I’m deeply sorry for every life that has been lost.”

As the disease continued to destroy lives and sear a place in the nation’s collective memory, the prime minister told a Downing Street press conference: “It’s hard to compute the sorrow contained in that grim statistic.”

Mr Johnson said he took “full responsibility for everything the government has done” during the pandemic, which has seen the UK bearing one of the heaviest tolls in terms of loss of life and economic damage.

The devastating impact was never envisaged at the start of the outbreak in March last year when Patrick Vallance, chief scientific adviser, said that keeping deaths below 20,000 would be “a good outcome”.

Nor did chancellor Rishi Sunak have any inkling of the impending economic catastrophe when, in his Budget of March 11 2020, he announced an apparently eye-watering £12bn to contain the damage.

Mr Sunak was widely seen at the time as having erred on the side of caution by deploying such a large sum to protect the economy from the pandemic. Covid-related spending by the Treasury has now hit £280bn.

Chart showing that the UK has passed 100,000 Covid-19 deaths according to three different measures. The government’s headline metric of deaths within 28 days of a positive test climbed to 100,162 on Tuesday; the more robust measure of deaths where Covid-19 was mentioned on the death certificate has reached 107,904; the total number of deaths from all causes in excess of the five year average had reached 98,000 by January 12, and will have passed 100,000 in the days since according to FT estimates

With 100,162 deaths now recorded — those who have died within 28 days of a positive Covid-19 test — Britain has the highest total of deaths of any European country. On that measure, 147 people have died for every 100,000 people in the UK, a figure only topped in the world by Belgium and Slovenia.

On more accurate tallies of total deaths compared with normal levels, there have been 99,000 deaths in the UK registered up to January 15, which will have occurred up to two weeks ago.

A Financial Times model estimates 120,200 excess deaths so far, again putting the UK in a position alongside Belgium, Spain and Italy as the worst in Europe and higher than the US.

Meanwhile, the UK has suffered one of the biggest economic hits of any major economy. On Tuesday, new IMF forecasts showed that the UK economy would not recover lost output until 2023, trailing the eurozone and far slower than the US which would achieve that milestone this year. Britain’s economic performance would be on a par with Spain and Italy, the fund said.

The reckoning for Mr Johnson’s government has already started. The prime minister’s failure to swiftly order lockdowns last spring and last autumn has been blamed by many for the high death toll.

Keir Starmer, Labour leader, said on Tuesday that passing the 100,000 milestone represented a “national tragedy”.

He has repeatedly blamed the government for exacerbating the crisis by failing to act quickly enough. Earlier this month he told MPs: “This is not just bad luck, it’s not inevitable, it follows a pattern.”

The catalogue of errors — from Dominic Cummings’s lockdown-breaking visit to Durham to the bungled programme to buy protective equipment, the shambles over test and trace and the school exam fiasco — is familiar.

Chart showing the UK has suffered one of the highest Covid-19 mortality rates in the world, suffering 1,475 Covid-linked deaths per million inhabitants, which ranks third globally behind only Belgium and Slovenia

One of the greatest concerns has been how the virus spread in care homes causing 30,000 deaths in the first wave. The latest statistics from the Care Quality Commission showed that in the week ending January 22, there were again the highest number of Covid-19 deaths of residents since early May with 1,705 fatalities, up 32 per cent on the previous week.

But the prime minister argues the “time is not right” for a public inquiry to learn the lessons. The hope in Downing Street is that by the time it happens, the grim era of Covid-19 will be firmly in the rear-view mirror.

Although Mr Johnson’s personal approval ratings crumbled last year, even his opponents admit that mistakes made in the handling of Covid-19 may not ultimately cost him his premiership.

One leading Conservative MP said the prime minister now had “his escape narrative” and that if the rollout of the vaccine programme continues to be successful then people may forgive earlier errors.

One senior Labour MP said many voters felt Mr Johnson had been dealt an impossible hand: “The benefit of the doubt runs deep in the British psyche. People ask: ‘Would you have done any better?’”

Chart showing that all measures of UK Covid-19 deaths have climbed steeply this winter, reaching heights not seen since the April peak. Deaths where the death certificate mentioned Covid have climbed to 1,100 per day in January, while deaths within 28 days of a positive test reached 1,200 on January 18. Excess death registrations are tracking slightly lower, but reached 928 per day in early January.

Polling suggests that the public’s view of Mr Johnson’s handling of the virus is critical but nuanced. A YouGov poll on January 15 found that 63 per cent of people thought the government had handled the pandemic badly, compared with 33 per cent who thought it had done well.

But a separate YouGov poll last October found that while 45 per cent thought Mr Johnson had done a bad job and had made crucial avoidable mistakes, some 46 per cent agreed that he had “made mistakes but has done as well as he reasonably could have done under the circumstances”.

The public mood could swiftly change if the vaccine programme is derailed or if the promise by Matt Hancock, health secretary, of a “Great British summer” turns into a gloomier reality of continued lockdowns and travel restrictions.

But senior Conservatives say the Number 10 narrative for 2021 is already prepared: it will stress the national ingenuity and resolve that carried the country through another dark hour.

In an evocation of wartime, Mr Johnson on Tuesday promised a national “moment of commemoration” after the pandemic ends to “remember everyone we lost and to honour the selfless heroism of everyone on the frontline who gave their lives to help others”.