Rishi Sunak will face a test of his leadership in two by-elections on July 20 caused by Boris Johnson and an ally.
The former prime minister quit his Uxbridge and South Ruislip seat to avoid the judgment of the privileges committee.
The cross-party panel subsequently recommended he should have faced a 90-day suspension for deliberately misleading MPs over partygate and his conduct in attacking the committee.
Another contest will be held in Selby and Ainsty, triggered by Nigel Adams who quit as a Conservative MP after being denied a peerage in Mr Johnson’s resignation honours list.
Mr Johnson held his west London seat with a majority of 7,210 in 2019 but Labour hopes to take advantage of the Tory turmoil to win.
Labour has always come second in this seat at general elections and polled 38 per cent of the vote in 2019, 15 percentage points behind Mr Johnson.
The Tories announced Steve Tuckwell will be their candidate in the seat.
In Mr Adams’ seat, he took 60 per cent of the vote and won a majority of 20,137 in 2019.
Labour came second with 25 per cent of the vote, 35 percentage points behind the Tories.
The Tories announced that Michael Naughton has been chosen to fight to retain the seat for them.
The prime minister also faces the prospect of another by-election, after Nadine Dorries said she would quit her Mid Bedfordshire seat with immediate effect.
However, that contest has been delayed after she vowed to stay on while she investigates how she was denied her expected peerage in Mr Johnson’s resignation honours.
But in a sign the Tories are gearing up to defend the seat – where Ms Dorries notched up a huge majority of 24,664 at the 2019 general election, some 60 per cent of the vote – Cabinet minister Oliver Dowden was out on the campaign trail on Thursday.
The Liberal Democrats hope to spring an upset there, despite the huge swing needed.
