THE number of trade unionists signing up as Labour supporters to vote in the leadership election could reach six figures, a party insider told the Star yesterday.

Campaign for Labour Party Democracy (CLPD) spokesman Jon Lansman made the prediction yesterday after Labour published new membership figures.

As well as 246,469 full members, the statistics show that the party currently has 9,115 registered supporters and 3,788 affiliated supporters.

In a bid to open up its leadership elections, Labour has invited the public to join as registered supporters for a £3 fee, while members of Labour-linked trade unions can become an affiliated supporter for the same price.

Labour issued the latest sign-up figures after the Evening Standard newspaper reported yesterday that twice as many affiliated supporters had been signed up as registered supporters.

But the statistics show that is not the case.

Mr Lansman explained that it was likely that trade unions had not yet handed over the details of members they have recruited.

He believes Labour will “certainly” have over 100,000 affiliated supporters before August 12, the final day to join in order to vote in the leadership election.

“I would expect the number of affiliated and registered supporters to rise significantly over the course of the campaign. It’s very early days,” he said.

“There’s no question we’ll be in six figures if you combine registered supporters and affiliated supporters.

“But I think we’ll probably be in six figures for each section. I think we will certainly have over 100,000 affiliated supporters.”

The number of new supporters could provide a boost to left-wing leadership candidate Jeremy Corbyn’s campaign, though turnout among union members in Labour’s 2010 contest was below 30 per cent.

Unaffiliated union PCS leader Mark Serwotka was among high-profile figures at Saturday’s anti-austerity protest to call on the public to sign-up and vote for Mr Corbyn.

Hustings for members of Labour’s 15 affiliated trade unions will be held in London next Tuesday.

Unite, GMB, Unison and other unions are expected to make a decision about which candidate to support.