Labour firebrand Rebecca Long Bailey is heading for humiliating third place in the party’s leadership race, it has been claimed.

Sources say the ‘Corbyn continuity candidate’ is trailing behind rival Lisa Nandy and clear favourite Sir Keir Starmer in a private survey of those entitled to vote in the Labour contest.

The forecast comes amid reports that her running mate, deputy leadership candidate Angela Rayner, is cutting back on appearances with Ms Long Bailey because her campaign is faltering so badly.

he Mail on Sunday has been told that a private poll of party members and affiliates has Rebecca Long Bailey in third place behind Wigan MP Ms Nandy, who has not served on Labour’s frontbench since resigning in 2016 in protest at Mr Corbyn’s management

The news emerged amid a campaign row over a mailshot sent out last week by Sir Keir to all 500,000-plus party members, thought to have cost at least £250,000.

At a party hustings yesterday, the leadership favourite said he would declare in due course how it had been funded.

But critics of Sir Keir are calling on him to provide details of the donors before ballot papers for the leadership contest go out tomorrow. Most party members are expected to vote by the end of the week.

Docker’s daughter Ms Long Bailey appeared to cement her reputation as Corbyn’s anointed heir last week by promising to offer the outgoing leader a top job on her frontbench.

Sources say the ‘Corbyn continuity candidate’ is trailing behind rival Lisa Nandy, left, and clear favourite Sir Keir Starmer, right, in a private survey of those entitled to vote in the Labour contest. Sir Keir and Lisa Nandy are pictured above at a Labour leadership hustings

But despite being endorsed by Corbyn ally John McDonnell, she has lagged behind Sir Keir, who has courted the party’s grassroots membership and who last week received the backing of former Momentum national co-ordinator Laura Parker.

Now The Mail on Sunday has been told that a private poll of party members and affiliates has her in third place behind Wigan MP Ms Nandy, who has not served on Labour’s frontbench since resigning in 2016 in protest at Mr Corbyn’s management.

A party source said: ‘It may be that Keir’s Leftie bank manager-style campaign is unstoppable, but it’s embarrassing for Long Bailey if she can’t beat Nandy given all the advantages she had. She’s been Corbyn’s anointed heir for years but it looks as though she’s blown that.’

The result will raise hopes in the Nandy camp that she could be the eventual victor by coming a close second to Sir Keir – and then picking up enough ‘second preference’ votes to win under the poll’s complex rules.

Ms Long Bailey’s campaign denied she was trailing in third place, claiming she was actually closing in on Sir Keir in first.

The Rayner camp said it was not limiting appearances with Ms Long Bailey.

Sir Keir’s campaign said the mail-drop was normal practice in a leadership contest and promised that ‘our donations will be published in line with the usual process’.