A fierce political row has broken out after police announced they were dropping a probe into allegations of fraud at Redbridge Labour.
Tory MP Bob Neill wrote to Scotland Yard back in July asking officers to investigate union involvement in the Ilford North constituency, which includes wards in Wanstead and Woodford.
He claimed there were reports that Unite had offered its supporters free Labour Party membership in exchange for attending a constituency meeting with its General Secretary Len McCluskey.
It came in the wake of allegations that Unite had tried to "fix" the Labour selection process for the Falkirk constituency in Scotland - claims the union strongly denied.
But this week the Met said it had found no evidence of wrongdoing at Ilford North or at Lewisham, a second constituency that Mr Neill also raised concerns about.
A Met spokeswoman said: "This matter has been assessed and there is no evidence of any offence.
"No further action will be taken".
In response, a spokesman for the London Labour Party said: “When Bob Neill wrote to the Metropolitan Police, Labour said this was a stunt and there was no evidence to support his ridiculous and untrue claims.
"Now the Met’s Special Investigation Team have confirmed there is no evidence of any criminality, Bob Neill and the Conservative Party should apologise to the police...and to Londoners for wasting valuable police resources on a political stunt.”
Mr Neill said he had not been contacted by the police to say they were dropping the investigation.
He told the Guardian: "unless and until I do, I am not going to comment on self-serving speculation by the Labour Party."
Mr Neill had previously said in his letter to the Met that if the allegations about Ilford North were proved then arguably there would be a breach of the Fraud Act 2006 under the terms of false misrepresentation or fraud by abuse of position.
Lee Scott, the Conservative MP for Ilford North, told the Guardian: "I don't comment on other political parties on things like this.
"I had no involvement in any of it [the letter to the Met]".