Labour is to refer its report on alleged irregularities in the selection of an election candidate in Falkirk to the police, a senior party source said today.
Ed Miliband is engaged in a row with Unite general secretary Len McCluskey over accusations the union crammed the constituency party with 100 or more members whose subscriptions were paid by the union, some of them without their knowledge.
Speaking on Friday afternoon, Ed Miliband said Labour would "select its candidates in a fair and transparent way".
"Instead of defending what happened in Falkirk, Len McCluskey should be facing up to his responsibilities. He should not be defending the machine politics involving bad practice and malpractice that went on there, he should be facing up to it," he said.
"It's wrong because we had members being signed up without their knowledge, bad practice, malpractice and frankly instead of defending that kind of thing Len McCluskey should be condemning it.
"Let nobody be in any doubt, there is only going to be one outcome to this: the Labour Party will act in a way that upholds the integrity of our party, the integrity of our party members and the integrity of ordinary trade union members.
"I will not allow the good name of the Labour Party to be undermined by the behaviour of a few individuals."
Miliband has been accused by Unite of leading a "smear" campaign against the union after the Falkirk selection controversy escalated into a full-blown public bust-up.
McCluskey said he had "no trust" in the party's handling of the affair as the Opposition leader's chief election co-ordinator, Tom Watson, resigned over the issue and two party members were suspended.
In an incendiary letter to Labour's general secretary Iain McNicol, he said a party inquiry into claims the union tried to stitch up candidate selection was a "disgrace" and demanded an independent inquiry.
"I am obliged to uphold the integrity of Unite, and I can no longer do so on the basis of going along with the activities of a Labour Party administration in which I can place no trust," Mr McCluskey wrote.
"I will therefore be publicly proposing that an independent inquiry be held into all circumstances relating to Falkirk CLP and the conduct of all parties involved."