The Labour party has banned over 200 people who stood as Green Party candidates at the general election from voting for its new leader.
Party officers told Channel 4 News that it has booted out 1,200 people who had signed up as party supporters in order to vote in the general election.
As well as 13 Conservative candidates and 37 candidates for the left-wing Trade Union and Socialist Coalition, 214 Green Party candidates were expelled as supporters.
Labour staff are said to be working overtime to check the eligibility of the thousands of people who have signed up to vote in the election.
For a £3 fee anyone who supports the aims and values of the Labour Party and is not a supporter of an organisation opposed to it can sign up to vote for the next leader.
The left-wing frontrunner in the contest, Jeremy Corbyn, is likely to appeal to supporters of TUSC and the Green Party, who have some similar policies.
Many members of those parties are thought to be former Labour members who defected during the more right-wing New Labour leaders.
“Many Greens are delighted to see Corbyn doing well – because we have some similar values, policies especially opposition to austerity,” @Heather_c_c, a Green Party member, tweeted.
Other people joining the party from outside organisations have joined for more nefarious purposes, however.
Labour leadership: The Contenders
Labour leadership: The Contenders
1/4 Jeremy Corbyn
Jeremy Corbyn readily admits he is only standing to ensure the left of the party is given a voice in a contest dominated by candidates promising to move the party towards the centre-ground of British politics
Profiles by Matt Dathan
2/4 Andy Burnham
Andy Burnham is the current front-runner to win the leadership election according to bookmakers, but the fact that the Conservative party leadership hopes he wins shows the task that awaits if he is Ed Miliband’s successor. He will have to find a way of distancing himself from both the last five years under Mr Miliband and the Blair and Brown years, during which he served in the Cabinet
3/4 Yvette Cooper
Yvette Cooper will also face a battle in convincing voters she offers a sufficient break with the past, having served in Gordon Brown’s Cabinet and she played a key role in Mr Miliband’s team as shadow home secretary. The fact that her husband is Ed Balls will not have a negative impact internally but voters are not likely to look favourably on the prospect of Mr Miliband’s ousted shadow chancellor entering Downing Street if Ms Cooper wins in 2020
4/4 Liz Kendall
Liz Kendall faces criticism over her lack of experience – she was only elected in 2010 and has no experience of serving in government and wasn't even in Ed Miliband’s shadow cabinet. But that very lack of experience means she can make a pitch as the only candidate offering real change and a real break from the Blair/Brown/Miliband years
Last month the Conservative-supporting Daily Telegraph newspaper urged its readers to join the party to swing its leadership in favour of Jeremy Corbyn.
Some Conservatives have said they do not think Mr Corbyn would be a good Labour leader and that he would be easy to defeat at a general election.
A poll last night showed Mr Corbyn winning the leadership by a landslide in the first round of voting. The other candidates in order of ranking were Andy Burnham, Yvette Cooper, and Liz Kendall.
Voting in the contest commences this weekend after the voter sign-up deadline, with the winner announced at a special party conference in September.