MOMENTUM is planning mass canvassing events in the constituencies of MPs that have defected from Labour to form a “Blairite-Tory coalition.”

The grassroots left-wing group said yesterday that it wants to inform constituents that their parliamentary representative has “left Labour and joined a coalition with former Tory MPs” ahead of any by-elections triggered as a result of the departures.

It comes after eight MPs left Labour to form the Independent Group and were joined by three breakaway Tories yesterday.

Events will be held in Streatham, Stockport and Penistone and Stocksbridge, the constituencies of former Labour MPs Chuka Umunna, Ann Coffey and Angela Smith, with the first event taking place in the next few weeks.

Luciana Berger, Mike Gapes, Chris Leslie and Gavin Shuker had also announced their resignation from the party on Monday, followed by former Labour Friends of Israel chair and Enfield North MP Joan Ryan on Tuesday.

Yesterday, their new grouping was joined by Tory MPs Heidi Allen, Anna Soubry and Sarah Wollaston, with Ms Soubry accusing Prime Minister Theresa May of letting the “hard-line anti-EU awkward squad” take over the Conservatie Party.

The defections prompted TSSA union leader Manuel Cortes to warn May she was “finished” and should “go – and take her stinking Brexit deal with her.”

But he warned Labour MPs against further desertions, branding their idea of the centre ground a “myth.

“It is no political oasis – it’s a political sink hole,” he said. “You really can’t team up with these dissident Tories whose votes have helped decimate our communities with austerity.”

Momentum has also launched a petition calling for by-elections in the seats of splinter group MPs.

The group pointed to a YouGov poll conducted after the 2017 general election which showed that just 6 per cent of Labour voters backed the party because of their local candidate, with 28 per cent saying they backed the party because of its manifesto and 15 per cent because they were anti-Tory.

In the hours after the splinter group formed, Momentum raised more than £15,000 in small donations from members to fund its canvassing events.

Momentum national co-ordinator Laura Parker said: “Their constituents voted for a Labour MP standing on a Labour manifesto. Now they’ve left the party and joined a Blairite-Tory coalition standing on a completely different platform.

“This is not what their constituents voted for. The only fair and decent thing to do is give their constituents a choice and call a by-election.

“Polls show the vast majority of Labour voters back the party and the policies, not individual candidates. These splinter group MPs ran in 2017 on a manifesto of public ownership, scrapping tuition fees and ending austerity.

“Now they’re working hand in hand with the Tories, they’ll revert back to an agenda of privatisation, deregulation and tax cuts for the wealthy.

“This is unfair, undemocratic and dishonest.”

The splinter group was accused yesterday of having broken data protection law, after the Labour Party shut down its campaign tools website.

Labour said that protected data that it holds about individuals was accessed.

A party spokesperson told the Labour List website: “We have become aware of attempts to access personal data held on the party’s systems by individuals who are not authorised to do so.”

The organisation is registered through Gemini A Limited, a private company owned by defector Mr Shuker, and is not a formal political party registered with the Electoral Commission watchdog.

This has raised concerns over transparency, as private companies do not have to declare donations.