LABOUR MPs will launch a new rebel group in the Commons to defy Leftie boss Jeremy Corbyn.

They are secretly plotting a “party within a party” if he wins next month’s leadership challenge.

5 Battle is on . . . rebel MPs plan a 'party within a party' to take on radical Corbyn Credit: PA:Press Association

5 In the race . . . Labour MP Owen Smith is up against Jeremy Corbyn in the leadership contest Credit: Getty Images

At least 80 MPs are ready to join the new faction, which will have its own policies, spokesmen and whips.

Glum moderates fear Mr Corbyn is on course to defeat Owen Smith in the leadership battle.

So they will join the Co-operative Party, which merged with Labour in 1927, and sit in Parliament under two banners.

About 30 are already members of the Co-op and hold fortnightly meetings.

5 Speaking up . . . rebel MPs might apply to John Bercow to be the official Opposition Credit: Ruckas

If the hard-Left try to deselect any of them, they will apply to Commons Speaker John Bercow to be the official Opposition.

Rebel leaders believe expanding the established Co-op would be better than staging a breakaway party, like the SDP in the 1980s.

It would keep MPs together rather than forcing a “stay or go” dilemma on them.

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A source said: “Some MPs for the sake of their sanity want some formal way of organising.

“The Co-op is established as an official entity and could be a means of doing that.”

5 Ready for take-off . . . Labour MP Stella Creasy has joined the rebel group Credit: Getty Images

5 Bridg-en the gap . . . Andrew Bridgen says Labour MPs want Theresa May to call an election Credit: Rex Features

Co-op members include John Woodcock, Stella Creasy, Jonathan Ashworth, Gareth Thomas and Louise Ellman.

MPs have consulted constitutional experts and lawyers.

Ballot papers go out to Labour members tomorrow and the new leader will be announced on September 2.

Last night Tory MP Andrew Bridgen claimed Labour MPs who expected Mr Corbyn to win were begging the Conservatives to call an election “to finish him off”.

“The Conservative Party should play politics like chess while Labour get on with their unending game of lots of snakes and no ladders.”