Keir Starmer has reason to celebrate this morning after his party triumphed overnight in both the Mid-Bedfordshire and Tamworth by-elections. Both on paper are safe Tory seats that aren’t even on Labour’s target list.

Despite this, Starmer’s party managed to overturn a Tory majority of 19,634 in Chris Pincher’s old seat, which was last Labour in 2010. In Mid-Bedfordshire – Nadine Dorries’ former seat – Labour won out in a three-way fight for the constituency that has been Tory since its creation. Overturning a Tory majority of 24,664, Labour won 13,872 votes to the Tories’ 12,680 and the Liberal Democrats’ 9,420.

In both votes, the Tory candidate was close behind in second place by around 1,000 votes. However, that will offer little comfort to concerned MPs who are far more likely to focus on the vote swing. The swing from the Conservatives to Labour in Tamworth was 23.9 per cent and in Mid Bedfordshire it was 20.5 per cent. As the polling expert Professor John Curtice put it on the BBC, this is ‘extremely bad news’ for the Conservatives. The Selby by-election over the summer also saw a swing of over twenty per cent. Curtice says the last time the UK has seen such swings in by-elections was the 1992-1997 parliament. MPs don’t need a reminder of what followed: a Labour landslide.

The results suggest the current polling is correct and that Starmer is on course for a majority

Unsurprisingly, Starmer has been quick to cite the results as evidence the public is ready for a Labour government: ‘Voters across Mid Bedfordshire, Tamworth and Britain want a Labour government determined to deliver for working people, with a proper plan to rebuild our country.’ It’s notable that in all the media interviews with Labour frontbenchers and the two new MPs, Alistair Strathern and Sarah Edwards, they have been at pains to say that Tory voters have moved to Labour.

Of course, the usual caveats apply. By-election results don’t tend to offer an accurate read on what exactly would happen in a general election. They have low turnout (in Tamworth it was just 35.87 per cent) and tend to see protest votes against the governing party. It’s also the case that the circumstances that these by-elections were triggered by – a row about peerages and sexual harassment allegations – made it harder for the Tories. But that said, the results suggest the current polling is correct and, were an election to be held tomorrow, Starmer is on course for a majority.

How will Sunak respond? Tories out on the airwaves have been quick to point out that the election is not tomorrow – it’s unlikely to be for a year so they have time to turn things around. It’s likely Sunak will come under pressure from some in his party to offer more vision or even tax cuts as a response to the disappointing results. Speaking on the BBC, Robert Buckland, the former cabinet minister, said he wanted to see more vision from Sunak about what a Tory government would do with another term.

The Prime Minister will be reluctant to change course, however, and will try to get his party to look ahead rather than engage in a long post-mortem. Inevitably though, these results will add to a sense of fatalism in the party that the next election is all but lost.

Given the two new Labour MPs have small majorities around 1,000, the Tories will hope to win these former strongholds back at the next election. The bigger problem for Sunak is that all his MPs with smaller majorities will look at this and fear they are on course to lose their seat. Last night’s result will add to a sense of doom in the Tory party about what next year’s election has in store.