Labour’s deputy leader Tom Watson has warned that unless the party changes, more MPs will defect to the new Independent Group of MPs – following the seven who quit on Monday.
Westminster is also awash with rumours some Tory MPs could throw in their lot with the newly-created gang.
Here are some of the MPs that are likely candidates to defect, from both parties.
Anna Soubry (Conservative)
Top of any list of potential defectors has to be the MP for Broxtowe.
Anna Soubry, a former minister, is the most outspoken pro-EU MP on the Tory benches. She has repeatedly bemoaned not only Theresa May’s Brexit plan, but her abandonment of One Nation conservatism.
Retweets are not necessarily endorsements, but Soubry chose to highlight Chuka Umunna’s speech launching the new Independent Group on Monday. And she has worked closely with the former Labour MP on the People’s Vote campaign pushing for a second referendum.
Sarah Wollaston (Conservative)
Sarah Wollaston, the MP for Totnes, has already floated the idea she will fight the next election as an independent if the government peruses a no-deal Brexit.
In recent days, the pro-EU chair of the health committee has been targeted for deselection by Brexiteers in her local party. She has warned the “entryism” from the right is “destroying” the Conservative Party.
Heidi Allen (Conservative)
Heidi Allen, the South Cambridgeshire MP, is also under threat of deselection from her local party for her pro-EU views.
Allen has been a constant thorn in the government’s side with her criticism of its Universal Credit welfare system.
She has previously said she would resign the party whip if Boris Johnson ever became party leader.
Ian Murray (Labour)
Ian Murray, the MP for Edinburgh South, issued what looked like an ultimatum to Jeremy Corbyn after the gang of seven quit on Monday.
He told the Labour leader he had to decide whether he wanted to carry on presiding over “a culture of bullying and intolerance where his own MPs feel unwelcome”.
Earlier this week, he also dismissed the “ridiculous” loyalty pledge to Corbyn that was circulating online.
John Mann (Labour)
John Mann, the MP for Bassetlaw, is a long-time critic of Jeremy Corbyn’s leadership. And he hit out at those on the left of the party who were glad seven MPs had quit.
“Those celebrating their departure are people who are not spending time on the doorstep listening to voters. Every week brilliant activists are quietly quitting, seeing the Labour Party as not for them,” he said.
While Mann said there was a “fundamental flaw” in the party being focused on a pro-EU agenda, he said the defections were just the “first charge”.
Ian Austin (Labour)
It would not be a huge surprise if Ian Austin, the MP for Dudley North, was one of the MPs to decide to jump ship.
He said today he was “thinking long and hard” about whether to remain in the Labour Party. And he defended those who had already decided to leave.
“What my seven friends did yesterday is the opposite of careerism. It would be easy to keep your head down, promise loyalty, ignore the racism and extremism and keep your job,” he said.
This list is, of course, not exhaustive. BuzzFeed UK reported on Monday that around 30 Labour MPs were originally considering joining the breakaway group on Monday.