Labour supporters 'could pay' to pick mayoral candidate
Labour supporters could be asked to pay to select a candidate for London mayor under suggestions being put to members.
Registered backers, who are not full members, could be charged a "small sum" to vote in "open primaries", ex-party general secretary Lord Collins said.
He also suggested non-members could be asked to help choose Labour's parliamentary candidates in seats where party membership is down.
The Conservatives said the proposals would give more power to unions.
Lord Collins was asked to write his report for Leader Ed Miliband, who is attempting to alter the way Labour is organised and paid for.
Mr Miliband has said he wants to change the way members of trade unions affiliated to Labour fund the party, following a row with the Unite union over the selection of a canidate for Falkirk.
In future they would have to "opt in" individually, rather than being signed up automatically, he argues. Mr Miliband says this will boost membership and give Labour a larger activist base.Leadership contests
But, in his interim report, Lord Collins said changing the party's relationship with the unions would be "difficult to achieve".
"Ed does not want this individual relationship with trade union members to damage the collective relationship and the institutional links between the party and the union organisations," he wrote. "Ed wants to mend - not end - the link."
Lord Collins also posed questions such as whether, with fewer affiliated members, unions should retain a third of the votes in future Labour leadership contests.
His report asked whether trades unionists who chose to join Labour - which would be at a cut-price rate - should have the same rights as existing party members.
Labour sources said that asking open-ended questions was intentional as the party wants to have a genuine consultation with its membership.
Another of Mr Miliband's proposals is for an open primary in London's mayoral election in 2016, allowing non-members a say in selecting a candidate.
Lord Collins's report asked: "Should individuals who register as supporters in London ahead of the mayoral selection be charged a small sum to finance the administration of the primary?"
And Lord Collins suggested holding primaries involving registered supporters, as well as full members, in constituencies where "the local party has dwindled".
Conservative Party chairman Grant Shapps said open primaries would give trade unions "greater ability to influence selections".
"Instead of taking on the unions over fixing selections, Ed Miliband has once again backed down to his paymasters' demands", he added.
"These proposals would actually put more power over Labour in (Unite general secretary) Len McCluskey's hands."
TUC general secretary Frances O'Grady said: "I'm sure they'll come up with a sensible solution that ensures ordinary people keep a voice in politics so we can speak loudly on issues like the bedroom tax."
Any changes to Labour's rules will be debated and decided upon at a special Labour conference in March 2014.