Jess Phillips’ campaign to become Labour leader is hanging in the balance as her rivals compete for the support of the GMB trade union.

The Birmingham Yardley MP was missing from a hustings event organised by the union, whose support could prove crucial to the candidates still hoping to make it on to the final ballot paper.

Aides said her absence from the GMB event was due to an unavoidable appointment elsewhere, but Ms Phillips is expected to make a statement on the status of her campaign on Tuesday afternoon.

She acknowledged on Monday that it would be a “bold roll of the dice” for Labour members to elect her as leader.

Emily Thornberry, Jess Phillips, Rebecca Long-Bailey, Sir Keir Starmer and Lisa Nandy
Emily Thornberry, Jess Phillips, Rebecca Long-Bailey, Sir Keir Starmer and Lisa Nandy (Danny Lawson/PA)

Shadow Brexit secretary Sir Keir Starmer is the frontrunner in the Labour contest, having already secured his place on the final ballot paper as a result of nominations from the unions Unison and Usdaw and the Socialist Environment and Resources Association (Sera), an affiliate group.

Sir Keir, shadow business secretary Rebecca Long-Bailey, shadow foreign secretary Emily Thornberry and former shadow cabinet minister Lisa Nandy were all at the GMB hustings in London.

Candidates need the nominations of three Labour affiliates, including at least two unions, which amount to at least 5% of affiliate members.

The only other route on to the ballot paper is by receiving nominations from at least 33 constituency Labour parties (CLPs).

Ms Thornberry, who only scraped through the first stage of the contest and appears to face a battle to make it on to the final ballot, praised the role of unions as she attempted to woo the GMB.

“Together with unions, we can take on the big challenges working people face,” she said.

Earlier she told ITV’s Good Morning Britain she remains “in this to win it” and claimed she would “frighten the life” out of Boris Johnson if she became the next Labour leader.

The contenders will take part in a televised debate on February 17.

The hour-long Channel 4 programme will be hosted by Krishnan Guru-Murthy, with the audience asking questions.

The ballot for the leadership opens on February 21 and closes on April 2, with the results announced on April 4.