Keir Starmer knew he would shatter any semblance of political consensus in the UK over the handling of the Covid-19 pandemic when he called a press conference in London on Tuesday evening.
Britain’s leader of the opposition had for months broadly backed the government’s approach to tackling the crisis while finding plenty to fault with actual delivery.
On Tuesday Sir Keir made an unambiguous call for a different approach: a two-week national lockdown dubbed a “circuit breaker” to halt the surge in infections.
It was not an impulsive decision. A Covid-19 subcommittee of Labour’s shadow cabinet, featuring seven of the party’s most senior MPs, was already leaning towards the idea of a circuit breaker when it met on Saturday morning.
“We were looking at the data and the numbers increasing and it was obvious the country was sleepwalking into a disaster,” said one member. “The government knows that this is going to happen — so why don’t they take action now?”
Sir Keir accelerated his decision after Sage, the government’s committee of scientific advisers, published documents on Monday night showing it had recommended last month a two-week national lockdown. Boris Johnson, the prime minister, had instead adopted less stringent measures including the “rule of six” on gathering sizes and the 10pm pub curfew.
This proof that the government had ignored its own advisers was seen by Labour’s leadership as the moment for a political change of tack.
“Johnson parting ways with the scientists was the perfect opportunity for Keir to step in and call for a more science-led approach,” said one Labour MP. “It was harder for us to call for a different approach when the PM was actually following the scientific advice.”
The Labour leader also twisted the knife by suggesting that a circuit breaker would be a chance to “reset and rectify” some of the government’s mistakes, such as improving the test and trace system.
He appears to be channelling the public mood: the policy is supported by a margin of 68 per cent to 20 per cent, according to a snap poll by YouGov.
Ben Page, chief executive of pollster’s Ipsos Mori, said Sir Keir’s intervention was “not a stupid thing to do” given its popularity with voters.
“In terms of the left and right of politics, then crudely it is the right who are most anti-lockdown and the left most cautious,” said Mr Page. “This move is probably sensible politics for his base, but also quite popular with voters.”
Robert Colvile, director of the CPS think-tank, said the move was “clever positioning”, adding: “If Boris caves they look good. If he doesn’t, they can claim every extra death that follows could have been prevented.”
For now the move has, however, galvanised Tory support for Mr Johnson, who was cheered loudly by his backbenchers during Wednesday’s prime minister’s questions in the House of Commons.
Many of those MPs are loath to see greater restrictions, let alone what their leader called the “misery” of a national lockdown.
Mr Johnson and Sir Keir traded accusations of “opportunism” during their weekly Commons bout.
“Labour have said it themselves: they see this as a good crisis for the Labour party and one they want to exploit.’” said the prime minister. That was a reference to Kate Green, shadow education secretary, recently calling on activists not to “let a good crisis go to waste”.
Mr Johnson claimed a lack of logic in Labour’s embrace of a national lockdown even where incidence is low while dragging its heels over greater restrictions in areas of high incidence.
But Jonathan Ashworth, shadow health secretary, privately used the metaphor of “embers of a fire” which could still reignite to justify nationwide restrictions. even in areas — such as parts of Wales and south-west England — that still enjoy low rates of infection.
Since Sir Keir became leader of the Labour party in April he has sought to avoid political landmines such as Brexit, tax rises or “culture war” issues.
His stolid, unflappable manner has so far proved popular with the general public: a recent YouGov poll found 46 per cent of respondents thought he was doing well against 35 per cent for Mr Johnson.
The call for a temporary national lockdown carries some political risk, given the potential economic damage from an endless cycle of on-off lockdowns.
But the Labour leader said the overall economic cost would be far higher without the temporary break.
In addition, he has calculated that Mr Johnson will be forced into the circuit breaker before too long given the rising infection rates across the country. Indeed Mr Johnson told the Commons on Wednesday that he would not rule out a brief national lockdown.