Jeremy Corbyn’s supporters would launch a “stop Keir campaign”, a Labour MP has said as Sir Keir Starmer emerged as a leadership frontrunner.

The shadow Brexit secretary would beat Rebecca Long-Bailey 61 per cent to 39 per cent in a run off, according to a survey of Labour members by YouGov.

Neither candidate has yet declared whether they will stand or not, but Sir Keir is now the odds-on favourite to succeed Mr Corbyn, 4/9 with William Hill.

The election process will be launched next week with the new leader set to take over in March. Shadow foreign secretary, Emily Thornberry, and the shadow treasury minister, Clive Lewis, have announced they will stand for the party leadership.

The poll of 1,059 Labour party members put Sir Keir on 31 per cent for first choice votes, with 20 per cent backing Ms Long-Bailey, 11 per cent backing Jess Phillips, and Mr Lewis, Ms Thornberry, Yvette Cooper and Lisa Nandy trailing behind.

In a run-off vote between the two leading prospective candidates, Sir Keir would beat shadow business secretary Ms Long-Bailey, according to the survey.

The poll, carried out by YouGov for the Party Members Project, does not include members of trade unions linked to the Labour Party, including Unite the Union which has 500,000 Labour members.