Rishi Sunak’s pet theory that voters are relaxed about the level of legal immigration – so long as the government is in charge of it – and only really care about illegal immigration has just collapsed.

New polling from YouGov shows that among 2019 Conservative voters, concern about immigration and asylum is now running nip and tuck with the state of the economy as their number one political issue (61 per cent include the economy and 60 per cent immigration when asked to name the top three issues).

A vague undertaking from the Prime Minister about reducing immigration from the astronomical levels he has inherited isn’t going to cut the mustard

The NHS lags far behind in third place, mentioned by 43 per cent. Concern about immigration among Tory voters is on a sharply upward trend and threatens to reach highs last seen in late 2015 and 2016 in the run-up to the EU referendum.

This compares to a low water mark for migration anxiety in late 2019 and early 2020 when much of the Tory electorate presumably chose to believe (mistakenly) that Boris Johnson could be trusted to bring down volumes.

All this should not really come as a surprise to anyone who read the papers or watched the TV news as the unprecedented 606,000 figure for net immigration during 2022 was announced on Thursday and received saturation coverage.

The Tory record of promise-breaking on this issue, stretching all the way back to 2010, was well excavated too. And in the Commons, even Keir Starmer felt able to attack the Tories from a relatively migration-sceptic stance.

On the one hand there is some comfort in the latest YouGov figures for Sunak given that of his five key priorities, three mention the economy, one is about improving the NHS and one about getting a tighter grip on immigration by ‘stopping the boats’. So he is still in the right territory in general.

But on the other hand he has, in effect, had to pretty hastily add a sixth priority, which is to bring down the level of net legal immigration after admitting that it is ‘too high’. And the impression has spread among many Tories that Sunak simply doesn’t comprehend their anxieties about the issue, which run far beyond the impact on wages and jobs and into housing, transport congestion, public services capacity, social and cultural cohesion and local community spirit.

A vague undertaking from the Prime Minister about reducing immigration from the astronomical levels he has inherited isn’t going to cut the mustard given that it comes as an offer of recompense to voters who have been let down so often and for so long. It also came across as hugely under-powered, with the PM just not transmitting the persona of someone who is determined to significantly reduce the numbers of incomers.

He’ll simply have to do better and be more specific or a big chunk of the 2019 Conservative vote is going to sit on its hands come the 2024 general election.

In PMQs last week, Starmer rolled into vacant territory about the need to do more to train British workers for the one million plus employment vacancies that exist. Labour’s greatest potential weakness among the Red Wall voters it needs to win back has therefore been neutralised by a combination of Starmer’s opportunism and astonishing levels of Tory carelessness about honouring promises on a key issue for their voter tribe.

It is, to use the technical jargon, a big mess for Sunak’s Conservatives. No wonder he thought better of hanging Home Secretary Suella Braverman out to dry over that speed awareness course nonsense. She is the only front-rank minister who gives off eye-catching vibes about being prepared to go hard and upset the political establishment to bring down immigration.

Had he allowed her to fall, Sunak would have been even more exposed on this front. As it is, he needs her onside to extend his career at the top of politics very much more than she needs him in order to extend hers.

Given her keen nose for a kill as a Brexit Spartan who helped finished off Theresa May, and as a cabinet resigner who was in the thick of the downfall of Liz Truss, this is not a position with which Sunak should feel remotely comfortable.

A prime minister who finds himself having to say – or even think – ‘save me, Suella’ is in big trouble. But having zero comprehension of the ‘gut’ Conservative position on mass immigration has led him to this juncture. He was too posh to push immigration control and must now farm it out to someone who isn’t. Good luck with that, Prime Minister.