Pressed about the level of preparedness in government for the Covid-19 outbreak in February and March 2020, Mr Gove told MPs: "It was the nature of the coronavirus pandemic, a novel virus, that meant we had to adjust to the situation and while of course there are important lessons to be learned, and of course there were mistakes that we made, I would say two things. Many people were left to die in horrific circumstances", he said in testimony to lawmakers.
Asked about that, Johnson said: "Some of the commentary I've heard doesn't bear any relation to reality and what people want us to get on with is delivering the road map, and trying cautiously, to take our country forward through what has been one of the most hard periods that I think anybody can remember post war".
"Of course this has been an incredibly hard series of decisions, none of which we have taken lightly".
Britain's Health Secretary Matt Hancock arrives for a coronavirus media briefing in Downing Street in London on Thursday.
His claims about the prime minister and health secretary Matt Hancock rocked Westminster and tore a hole in the once seemingly close relationship between Cummings and Johnson.
"Cummings rains fire on No 10", read the front page of Britain's Times newspaper, while The Daily Telegraph accused the former adviser of seeking revenge on Johnson and Hancock during the hearing after he branded them "unfit" and dishonest.
In the Commons, Mr Hancock said the allegations levelled against him by Mr Cummings were "not true" and he later told a Downing Street press conference that the commitment he had given was to build the capacity to be able to test patients before discharge.
"We put £1.4 billion extra into infection control within care homes, we established a care homes action plan, I remember very clearly, to ensure that we tried to stop infection between care homes", Mr Johnson said.
Opposition Labour Party health spokesman Jonathan Ashworth said whether or not Cummings' allegations were true, the government had questions to answer. Johnson has announced there will be a full inquiry into the government's handling of the crisis, but not until the spring of 2022.
A mass vaccination campaign that started in December has brought confirmed cases and deaths down sharply, though Britain is now reckoning with a more transmissible new strain of the virus first identified in India.
"Tens of thousands of people died who didn't need to die", he said.
Scientists expect the variant to become the dominant one in Britain but they say existing vaccines appear to work against it. Nearly three-quarters of British adults have had one dose of a coronavirus vaccine, and 45% have had both doses.
Mr Hancock said it was "too early now to say" whether remaining social restrictions imposed to slow the spread of the virus could be lifted on June 21 as planned.
But asked again to clarify later in the press conference, he said: "My recollection of events is that I committed to delivering that testing for people going from hospital into care homes when we could do it".