The Labour Party’s membership has gone up by 114,000 since its defeat in December’s general election.
The figure was confirmed to the party’s National Executive Committee on Tuesday as it readies itself for a new leader.
Sir Keir Starmer, Lisa Nandy, Rebecca Long-Bailey and Emily Thornberry are still in the running to replace Jeremy Corbyn.
Another 14,700 people have paid £25 to be “registered supporters”, allowing them to vote for his successor.
The new leader and deputy leader will be announced on 4 April.
To make it onto the final ballot, candidates need the backing of two unions and one affiliate group – representing at least 5% of the membership – or nominations from 33 constituency Labour parties.
Only the shadow Brexit secretary, Sir Keir, and Wigan MP Lisa Nandy, have passed this hurdle so far.
However, the shadow business secretary, Mrs Long-Bailey, has the backing of the Unite union and 24 CLPs, while the shadow foreign secretary, Ms Thornberry, has four CLPs behind her.
Both contenders have until 14 February to garner the support.
Shadow education secretary Angela Rayner is the only deputy leadership candidate to have made it onto the ballot so far, with the support of four unions and 41 CLPs.
The other candidates running for the position are Scotland’s only remaining Labour MP Ian Murray, shadow equalities minister Dawn Butler, Tooting MP Rosena Allin-Khan and shadow justice secretary Richard Burgon.