Rishi Sunak should fend off assaults on his management if the Tories lose three as soon as solidly Conservative seats on this week’s by-elections.

A former Cabinet minister warned that it will likely be the “final straw” for a lot of MPs if all three are misplaced on Thursday.

Voters will go to the polls in Selby and Ainsty, Somerton and Frome, and Uxbridge and South Ruislip – the previous parliamentary house of Boris Johnson.

The veteran Tory expects some MPs will probably be so pissed off they'll ship letters to Sir Graham Brady, the chairman of the 1922 group of Conservative backbenchers, requesting a vote ­of confidence in Mr Sunak’s management.

They mentioned: “I think for a lot of my colleagues this would be the final straw. Everybody says you can’t change leaders with a year to go before the election – but what do you do when you have ­a leader who is not cutting ­the mustard?”

Exclusive polling for the Sunday Express by Omnisis discovered that almost half (46 p.c) ­of Britons don't assume he ought to stay ­as PM if all of the ­by-elections are misplaced.

Just three in 10 say he ought to keep within the job, with 24 p.c uncertain.

Another former Cabinet minister mentioned there may be “definitely” nonetheless time to revive the get together’s ­fortunes below a brand new chief, and urged Mr Sunak to contemplate whether or not he ought to keep in submit.

They mentioned: “I think quite frankly when we lose these ­by-elections this should be a moment when Rishi Sunak looks at himself in the mirror and ­­says: ‘Am I the right person to lead this party?’”

Describing the unhappiness in Tory ranks, they added: “People are so fed up in the parliamentary party. We are treated with such disdain, discourtesy, we’re ignored. If you raise an issue like migrants you’re accused of not supporting the Government... Quite frankly we need a complete clear-out of everyone in this current Government.”

MPs who're already anxious about holding onto their seats will develop extra frightened this week if Opposition events can overturn the 20,137 majority in Selby and Ainsty – the previous seat of Nigel Adams, a key ally of Mr Johnson – or the 19,213 majority in Somerton and Frome, previously represented by David Warburton, who was suspended over allegations of sexual misconduct, which he denies.

Some Conservatives imagine they're “in with a chance” on the subject of holding onto Uxbridge and South Ruislip (majority 7,210).

This is because of anger at London Mayor Sadiq Khan’s plans to increase the capital’s Ultra Low Emission Zone, which implies drivers of non-compliant vehicles ­should pay a day by day cost ­of £12.50.

An ex-Cabinet minister cautioned pissed off Tories towards trying to oust Mr Sunak if he suffers a hat-trick of losses.

Looking forward to the problem of successful the following election, ­they mentioned: “There’s nothing that could be done in terms of ­changing the leadership that would be helpful.”