UNITE union leader Len McCluskey has condemned an internal Labour report into the Falkirk selection row as a "shoddy farce" as he demanded a greater say over the party's future direction.

In his strongest intervention to date, Mr McCluskey hit back at accusations Unite attempted to manipulate the contest to pick Labour's candidate for the seat at the next election and insisted his organisation had obeyed rules introduced by ex-prime minister Tony Blair.

He also claimed that two union members suspended from the Labour party following the allegations would be cleared as he pledged to protect them from a "witch hunt".

The Conservatives seized on his call for a greater influence within the party to accuse Ed Miliband of failing to fundamentally change Labour's relationship with the unions.

The Labour leader has announced plans for sweeping changes, including an end to the automatic opt-in to party affiliation contributions for union members, following the outcry over the Falkirk allegations.

In a speech to union members yesterday, Mr McCluskey hit out at the party's handling of the issue.

"We were within the rules," he said. "Union Join was introduced in 2001 by Tony Blair and allowed unions to pay the first year's subscription of new members."

Describing the internal Labour party report into the claims as a "shoddy farce", he said: "Assertion was passed off as fact, allegation became grounds for conviction.

"It had not one plausible allegation of wrongdoing by Unite. Yet, that report is being used to trample on the rights of Labour members in Falkirk and to smear and slander our union. It suspended two of our members from the Labour party and unleashed the police on decent people. It is an utter, utter disgrace."

The selection process in Falkirk has been suspended and the local party put into special measures.

The Unite members suspended include Karie Murphy, once tipped as a front runner to win the contest to become Labour's candidate in the seat.