Mr Clark, the influential chairman of the Commons science and technology committee, stressed MPs were pursuing the issue of whether restrictions could be scaled back more quickly because “it’s on the minds of our constituents whose jobs depend on this”.
He asked Professor Whitty, who was appearing before the committee on Tuesday: “If we got to the end of April and the levels of infection, admissions to hospital, pressure on hospitals, ability and knowledge of the vaccine and its efficaciousness against new variants..all of these things had gone very well, would we still need to wait until June 21 just because we had set a date rather than be guided by the data?”
The ex-Business Secretary’s intervention is possibly the most significant so far from the Tory backbenches over the speed of lockdown easing, which is due to largely happen by June 21, and came as the seven-day Covid-19 rate in the capital fell to 45 confirmed new infections per 100,000 in the week to March 3.
Londoners are being urged by health chiefs and ministers to continue following the rules to keep downward pressure on coronavirus cases after the start of lockdown’s relaxation with schools re-opening yesterday.
Prof Whitty defended the Government’s roadmap out of lockdown, stressing the gaps between each stage were needed to gauge the impact of easing restrictions and that each step included significant relaxations.
“All the modelling suggests is that at some point we will get a surge in virus,” he stressed, as restrictions were eased.
“We hope it doesn’t happen soon, it might for example happen later in the summer if we open up gradually or because of the seasonal effect it might happen over the next autumn and winter.”
The surge would “find the people who either have not been vaccinated or where the vaccine has not worked,” he added.
“Some of them will end up in hospital and sadly some of them will go on to die.”
The health chief emphasised that he would “strongly advise” against any attempt to “concertina” the five-week interval between steps.
Ministers could look at whether more could be eased at some of the stages.
But he stressed: “If you look at the history of this, all around the world, is not full of countries and individual leaders wishing they had done more faster, it’s full of leaders who wished they had acted quicker and then been more careful as they take things off.”
He pointed to new Covid-19 surges on the Continent, warning: “It’s very easy to forget quite how quickly things can turn bad if you don’t keep a very very close eye on it.”
But Mr Clark stressed: “The striking comparison between this country and other European countries that are having to go back into lockdowns is that we have a much more effective vaccine roll-out programme, is it not?”
Prof Whitty responded: “If you are thinking about a surge in transmission, remember that the great majority of those who will drive the surge in transmission are not yet vaccinated and will not be vaccinated by Easter.
“So the idea that that is a ‘get out of jail card’ in terms of the surge in transmission, I think is to misremember where in the age spectrum the drive of transmission is and it’s in younger adults, not in those who have so far been vaccinated by in large.”
Prof Whitty added that “if you open up too fast, a lot more people die”.
He stressed that modelling shows that if a “steady” approach was taken to easing restrictions, waiting for far more people in the lower age groups to have been vaccinated, then the country would be in a “much better position” than going more quickly.
“If you start shunting things forward, you will very quickly get to these very high peaks,” he added.
Modelling data considered by the SAGE scientific panel has suggested that even under the most optimistic set of assumptions, at least a further 30,000 Covid-19 deaths could occur.
Mr Clark, though, suggested that the assumptions in the modelling had been superseded by better-than-expected results from the vaccine and higher take-up of the jabs.The senior Tory MP asked Prof Whitty: “Does that cause you to revise your view of what we should be preparing for?” in the summer.
Prof Whitty said the vaccine effectiveness looks to be at the “higher end of the expected range”, not “way out of the ballpark” but a “bit better than the central projection” and take-up was good, though he suggested this could fall in younger age groups.
He stressed that the modelling was an “indication of general principles” rather than a specific prediction.
But the models demonstrated that “if you open up too fast, a lot more people die”.
He told MPs that even opening up in a “steady way” such as in the road map would result in more deaths, but fewer than in a rushed release of restrictions.
He stressed it was important to wait for four weeks of data before making a decision on the next step of easing lockdown.
Without that gap “it’s pretty doubtful you would be in a position where you are going to be able to say ‘these data look so fantastically better, please take more risks here”’.“I think that seems a very unlikely situation, given how large these blocks of activity are.”
The Government’s Chief Scientific Adviser Sir Patrick Vallance echoed that view, telling MPs: “If you truncate that, you are essentially flying blind.“You might feel ‘oh, I can smell it going in a certain direction, it looks like this’, but you really want to know.”
Sir Patrick said it was inevitable that coronavirus cases would increase as restrictions on social mixing were eased, with modelling suggesting re-opening schools could push up the R-rate of transmission by between 10 per cent to 15 per cent.
He told MPs that Boris Johnson’s “road map” for easing lockdown in England was in line with the principles set by the SAGE committee and “consistent with minimising that increase as you open things up”.
Asked whether “data, not dates” was just a slogan, Sir Patrick told the committee “for us it is not”, stressing the importance of measuring the impact of changes to the rules.
Prof Whitty suggested the measures pencilled in for May 17, when indoor mixing of up to six people could be allowed, involved “significant risks”.
The April 12 measures are “a very big block”, with shops and outdoor hospitality due to open, he added, and May 17 “is a very significant block with a lot of stuff that is indoors for the first time, that is the point when we are really going to start to see some very significant risks accumulating, potentially”.