Will 'three-quid voters' decide next Labour leader?
After a recent speech in Leeds two or three people in their twenties approached Jeremy Corbyn pledging they would be voting for him in the Labour leadership election.
All freely admitted they were not members of the party, and had no intention of ever joining unless the veteran left-wing MP won the election and Labour adopted his manifesto.
So how is it that they can have a vote for the leader of a party even though they are not members?
The answer is that they are Labour's "three-quid voters".
In fact there are now 35,000 of them, which means they will make up around 10% of the eligible electorate when the Labour leadership ballot opens on 14 August.
"In this election virtually anybody can pay just £3 online and have the same power as long-standing members to choose the next party leader," I was told by Leeds North East MP Fabian Hamilton.
"This was one of the daftest ideas the party has ever come up with.
"This is infuriating many of my constituency members, some of whom have paid their subscriptions for 10, 15 or 20 years, attended meetings and actively campaigned in elections."
The idea of the "three-quid voter" came about as part of interim leader Harriet Harman's efforts to "widen the public debate" over the choice of the next leader after the disaster of the general election.
Hustings and campaign meetings would be opened up to non-members, but she and the shadow cabinet also agreed to a further radical move not taken by any other UK mainstream party in the past.
Anybody ticking a box on a web page confirming they "believe in the values of the Labour Party" and paying a one-off £3 fee would also be able to vote alongside fully paid-up members.
Unlike the 2010 leadership ballot when the controversial block voting system saw Ed Miliband scrape home with the backing of trade unions, this election was supposed to be more democratic, with every party member or registered trade union sympathiser having a vote.
Figures released on 5 August by the Labour Party's press office revealed there were 275,000 members and a further 35,000 trade unionists eligible to vote.
The large number of non-members who will now be issued ballot papers means they will have a big influence on who eventually emerges as the winner.
Left wing opportunists
Labour Party officials have been at pains to explain to me that there could be many reasons for those taking advantage of this option to have a vote without actually being a member.
Though my own experience at various leadership hustings and meetings in June and July all the "registered supporters" I have met so far tell me the same story - they are coughing up their three pounds to ensure Labour returns to its left wing roots.
There will also be at least another 20% of the full membership who will be voting for the first time in a Labour leadership contest.
These are the 65,000 new members who have signed up since Labour's defeat toppled Mr Miliband in May.
It is thought there could be as many more. Around 30,000 applications are being processed and the recruitment deadline runs until 5 August.
This big block of new members worries Bassetlaw MP John Mann as much as the £3 voters.
He suggested so little was known about these new members that the leadership election should be suspended until "proper checks" on them had been made.
In his view many who want to harm the Labour Party are exploiting the ease of getting a ballot paper in order to ensure an unelectable left winger becomes leader.
"People who opposed us, people who stood against us, anybody can roll up," he told me.
"Someone needs to check if they are Labour supporters and Labour voters. If so, they are welcome. If not we don't want you."
These concerns are dismissed by the Corbyn camp as coming from worried supporters of other candidates who appear to be trailing behind the veteran left wing MP.
Mr Mann and Mr Hamilton both nominated West Yorkshire MP and shadow cabinet member Yvette Cooper and are actively campaigning for her.
Mr Corbyn himself is on record as saying he only wants to be elected by those who have the best interests of the Labour Party at heart and disagreed with any suggestion of wholesale infiltration by left wingers trying to control the political direction of the party.
The Labour Party also shrugs off any suggestion of the voter qualifications being exploited by external factions.
It says strong measures are being taken to ensure only those who support the party will be allowed to vote with 45 officials working full-time sifting through the applications.