But raising the issue in the House of Commons on Thursday, the Tory MP Joy Morrissey said there should be a debate on the “democratic mandate” in Parliament.

Mr Rees-Mogg, the Commons Leader, replied: “Most of us know that we are elected because of the party that we support.

“All the studies have shown that the ‘personal vote’ Members of Parliament have is remarkably small, and people are aware that however much independents may be brilliant individuals, they very, very rarely get elected to this House.

“It is the party ticket that gets people elected and I know that bills have been introduced to this House in the past…on having a by-election if people were to decide to change party, and I think this is something worth discussing and debating.”

Mr Javid, the Health Secretary, said Mr Wakeford’s defection was “not good news” but “a decision for him”.

‘I feel sorry for the people of Bury South’

Asked if he thought there would be a by-election, he replied: “I feel sorry for the people of Bury South. They voted Conservative.”

A Labour source on Thursday indicated that there would not be a by-election, while a Conservative source pointed out that the party’s recent financial troubles may make it difficult to fight one.

Although defectors often face calls for a by-election, few ever call one.

Mark Reckless and Douglas Carswell, who defected to Ukip in 2014 and each won a by-election to keep their seats, are a notable exception.

Ms Reeves praised Mr Wakeford’s defection to the Labour Party, and told the BBC Radio 4’s Today Programme: “I’m happy to have him as a Labour MP and I’m looking forward to getting to know him.

She added: “He has looked at the Conservative Party and sees that they’re no longer fit to lead.

“He looks at the Labour Party under Keir Starmer, he sees that the Labour Party has changed.

“He also sees his old party the Conservative Party has changed and many people are drawing the same conclusion that the Conservatives and Boris Johnson are no longer fit to lead.”