BY-ELECTIONS threaten to cause misery for Prime Minister Rishi Sunak this week, as the Tories battle to save their seats in three crunch local polls, experts predicted yesterday.

Labour and the Lib Dems are both hoping to inflict blows to the government in Thursday’s by-elections in Uxbridge and South Ruislip, Selby and Ainsty as well as Somerton and Frome.

The Uxbridge and Selby polls were triggered amid the fallout from former PM Boris Johnson’s reaction to the privileges committee investigation and the row over his resignation honours list.

Pollster and political analyst Lord Hayward said that Britain has now “returned to normal mid-term politics.”

“What we’re looking at is a series of by-elections where people will naturally express their anger about the current government.

“Boris Johnson, in a curious way, managed to defy mid-term in some cases, although not necessarily in by-elections.”

The Tory peer added that the Conservatives could pay the “penalty” for the scandals in Mr Johnson’s government.

Mr Johnson had held the west London constituency of Uxbridge since 2015 prior to his recent exit.

Labour candidate and local councillor Danny Beales is hoping to become the area’s next MP.

But Conservative councillor Steve Tuckwell and the Tories are hoping that controversy around the Sadiq Khan-backed Ultra Low Emission Zone (Ulez) scheme will be enough to sway voters away from the opposition.

Labour has been campaigning hard in the Uxbridge seat, with the town potentially a key marker of the extent of Labour gains ahead of the next general election.

Outgoing Selby and Ainsty MP Nigel Adams recently resigned after being denied a peerage in Mr Johnson’s resignation honours list.

Barrister and district councillor Claire Holmes is fighting to keep the seat blue, but Labour strongly believes that 25-year-old Oxford graduate Keir Mather, a former CBI employee, is in with a chance.

Labour has said that victory in the North Yorkshire constituency would be the largest majority it has overturned since the second world war.

The old Selby constituency – with different boundaries – had a Labour MP between 1997 and 2010.

In Somerton and Frome, the by-election could offer an opportunity for the Liberal Democrats to gain a seat, with some seeing victory there as a near certainty.

Tory MP David Warburton resigned amid allegations of sexual harassment and cocaine use.

He had held the seat since 2015 when the Tories took it from the Lib Dems.

Mr Warburton was condemned by Commons yesterday after claiming the allegations – which are currently being reassessed after he was found guilty by the Parliamentary Commissioner for Standards — were withdrawn and that he had been “vindicated.”

In response, a Commons spokesperson said: “Divulging the details of an investigation, particularly through proactive briefings to the media, poses a significant risk to the wellbeing of others who may be involved in [the Parliament’s Independent Complaints and Grievance Scheme] case.

“We strongly condemn such egregious breaches of confidentiality for that reason.”