Senior allies of Labour leader Jeremy Corbyn are considering plans to create a second deputy head of the party, a move that could undermine the incumbent Tom Watson.

The idea would involve the newly established position being held by a woman but is likely to enrage many Labour MPs who see Mr Watson — deputy leader since 2015 — as one of the last bulwarks against the party’s takeover by Mr Corbyn’s hard-left faction.

Any firm proposal for a second deputy leader would be sold to Labour members as an attempt to improve the party’s gender balance, but the subtext is clear, according to Mr Corbyn’s allies. “If we get another deputy it will render the existing one kind of pointless,” said one of Mr Corbyn’s associates.

The idea is still in its infancy and is not expected to be put to the vote at the Labour conference this autumn. It was not discussed at a meeting of Labour’s ruling national executive committee this week.

But with Mr Corbyn having cemented his position at last month’s general election, when the party made gains, several of his allies said that plans for a second deputy leader who would be elected by Labour members had been discussed seriously.

“It’s an idea that has been mooted in Westminster, certainly,” said one.

A second described it as “an aspiration” rather than firm plans. “It’s really about getting a woman as a deputy more than anything else,” he said.

Mr Corbyn’s spokesperson declined to confirm or deny the story.

Some supporters of Emily Thornberry, the shadow foreign secretary, are encouraging her to run for the second deputy position if it is established — and have been sounding out potentially sympathetic MPs.

Last week she stood in for Mr Corbyn at prime minister’s questions in the Commons, reflecting her senior role in his top team.

A spokesman for Ms Thornberry declined to comment but people close to her denied that she is planning to challenge Mr Watson, pointing out there was no vacancy at present.

Some of Mr Corbyn’s supporters on social media have for months floated the idea of a senior female MP such as Ms Thornberry challenging directly for the deputy leadership.

Mr Watson is an unpopular figure among many of Labour’s pro-Corbyn members.

Last summer he asked Mr Corbyn to step down after a failed coup by MPs against the leader which resulted in the resignation of more than 60 shadow ministers.

Mr Watson was an ally of former prime minister Gordon Brown. He was accused of involvement in a rebellion that prompted Tony Blair to step down as prime minister in 2007.

Mr Watson took up his current role when Mr Corbyn was elected Labour leader by party members in 2015. Mr Corbyn’s supporters realise that to challenge Mr Watson’s position under Labour party rules they would need the backing of close to 50 MPs, which they would struggle to achieve.

But creating a second deputy leader would be a way to undermine Mr Watson without directly challenging him, said one person familiar with the discussions.

The concept would be hard to challenge, meanwhile, given its progressive nature. “It would be welcome as the leader and deputy leader should be gender balanced,” said one of Mr Corbyn’s supporters.

Meanwhile, some of Mr Corbyn’s allies are considering moves that would further lock in the hard left’s grip on Labour.

Some Labour insiders believe that staff at the party headquarters in London are vulnerable to being ousted after they failed to predict the party’s strong showing at the election.

Jon Lansmann, who founded the Momentum pro-Corbyn grassroots group, told the Observer newspaper last week that party members should be given greater power over selecting MPs and the Labour leader.

He said he would back attempts by local parties to make changes at next year’s Labour conference that could see branches handed the power to nominate leadership candidates, instead of the current system in which MPs and MEPs are gatekeepers for the process.

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