Two parliamentary by-elections are set to be held in Wakefield and in Tiverton & Honiton on the same day next month following the resignation of two Conservative MPs.

The Tory chief whip, Chris Heaton-Harris, is expected to move the writ — a formal process effectively triggering a by-election — on Tuesday, with a vote likely in both constituencies on 23 June.

The by-election in Wakefield follows the resignation of the former Tory MP Imran Ahmad Khan, who was convicted last month at Southwark Crown Court of sexually assaulting a 15-year-old boy.

Sir Keir Starmer told a meeting of the Parliamentary Labour Party (PLP) on Monday evening that the vote would be an “enormous test� for the party, with the Boris Johnson’s party likely to “throw the kitchen sink at it�.

The former Labour stronghold turned blue at the 2019 election, and it is one of many constituencies that Sir Keir must win back if he wants to prove he has what it takes to end the Tories’ 13-year tenure in No 10.

On Sunday, Labour members chose NHS worker Simon Lightwood to fight for the party, but the process was overshadowed last week amid internal infighting over the selection of candidates for Labour’s shortlist.

On Thursday the executive committee of Wakefield’s Labour Party voted to resgin en masse over the national party’s handling of the process and accused officials of breaching the rule book.

Meanwhile, the vacancy in Tiverton and Honiton follows the resignation of Neil Parish, who quit last month after he admitted watching pornography in the Commons chamber in a “moment of madness�.

After a 12-year stint in the Commons, Mr Parish, who has described his own actions as “immoral�, was at the centre of a political storm after two female colleagues reported him to party officials.

Mr Parish last won the Devon seat for the Conservatives in 2019, with 60 per cent of the vote share and a huge majority of 24,239 votes.

Speaking last week, the former Tory MP, however, also suggested he was taking “soundings� on standing as an independent in the forthcoming by-election triggered by his own resignation.

“It is an option for me and one that I could consider,� he said. “The only thing that may well stop me is the face my local party, my local activists, my local councillors, are friends. I don’t know if I want to do that to them.

“Some of the hierarchy in my own party, I suppose I wouldn’t have the same problem with doing it. At the moment, I’m taking soundings�.

Mr Parish suggested he could raise the funds to stand through some powerful backers within the farming community. “I don’t think I’m going there, but, it’s an option,� he said.

However, he added: “I will decide before nominations close. Don’t forget I have fought five local elections, two European elections and five parliamentary elections. I know how elections works and don’t forget, I’m a grassroots politician and I made my own way through the ranks�.