Media playback is unsupported on your device Media caption Harriet Harman: Allegations needed to be investigated

Labour is under pressure to publish an internal report that cleared Unite of claims it tried to rig the selection of a party candidate in Falkirk.

It found no rules were broken and two union officials - one the candidate - have been reinstated as members.

The Tories said Unite was "calling the shots" but Labour said it had acted to protect party interests amid a rift between its leadership and the union.

Karie Murphy later withdrew as the prospective general election candidate.

She said she had been "shocked and saddened" by what had happened but would no longer stand for the sake of "reconciliation and unity".

Unite is Labour's biggest single financial donor - it currently affiliates around a million members which results in fees to the party of around £3.25m.

'No apology'

Labour started seeking a candidate for the Falkirk seat when MP Eric Joyce announced he would be stepping down at the next general election in 2015 after he was convicted of assault at a Commons bar.

The party had been investigating allegations that Unite tried to sign up members without their knowledge in the constituency to ensure their favoured candidate, Ms Murphy, was chosen.

The claims sparked the row between Unite and party leader leader Ed Miliband, who later proposed widespread changes to Labour's links with the unions.

Labour's deputy leader Harriet Harman said there was no need for Mr Miliband to apologise to Unite.

Analysis The process of selecting a Labour candidate in Falkirk provoked the bitterest row between the party and the trade unions in a generation. This was no local difficulty. It had national and wide-ranging personal and political implications. Members of Unite were accused of using underhand means to try secure the nomination of their favoured candidate, Karie Murphy. She was close to the union's general secretary Len McCluskey, and worked for Tom Watson, the party's general election co-ordinator. He resigned from the shadow cabinet over the leadership's handling of the Falkirk allegations. In the wake of the row Ed Miliband announced sweeping reforms to his party's links with the unions - changes which are said to have cost Labour £1m in affiliation fees so far. Tom Watson now says it was rash of Labour to rush in to wide-ranging trade union reforms before the events in Falkirk had been properly investigated. Karie Murphy is said to feel battered and bruised - the reputations of some of those involved in this episode might yet suffer a similar fate.

"If serious allegations are made, it is the responsibility of the leader of the Labour Party to make sure they are properly investigated," she said.

"I also think it's right that we continue with the process of looking at the relationship of the unions and the Labour Party, and make sure that we change and modernise those relationships that Falkirk was the catalyst for.

"The outcome of the situation in Falkirk has no bearing on the importance for the future of getting a better relationship between Labour and the trade unions."

On Friday, Labour said an internal inquiry had found no evidence to suggest that rules were breached after "key evidence" was withdrawn.

It said neither Ms Murphy nor Stevie Deans, a fellow Unite member who was chair of the local Labour Party, had been found guilty of any wrongdoing.

The internal report - and a previous internal report into concerns over the selection process - have not been published.

'Buckle'

The Conservatives said it appeared to be a "stitch-up" designed to end a bitter row with Unite - Labour's biggest financial backer.

Party chairman Grant Shapps said "it would clear the air to publish the report and let everybody judge for themselves".

He said: "It now appears that pressure from the unions has caused Ed Miliband to buckle.

"Suddenly, he is saying 'don't worry about it it was nothing'... We need to see exactly what has happened."

A Labour spokesman said: "At each step Labour's general secretary and NEC [National Executive Committee] have acted quickly to protect the interests of the party.

"Since Labour began its internal process key evidence has been withdrawn and further evidence provided by individuals concerned."

Police were asked to investigate the matter but decided there were "insufficient grounds" to justify further inquiries.

But the case is also the subject of an investigation by the Information Commissioner's Office into claims that data protection rules may have been broken in the Scottish constituency.

'Terrible time'

Mr Joyce said questions remained over the events.

Media playback is unsupported on your device Media caption Eric Joyce MP says: "Victory for the leadership of Unite"

Tom Watson, the Labour MP who stood down from the shadow cabinet after the row, said people would be "raising eyebrows" after the party launched a "complete reassessment" of its relations with the unions on the basis the inaccurate report.

But he told BBC Radio 4's Today programme: "The basis for the report was a mess and Ed's office have been able to drill into that issue and realise that."

Mr Watson said it appeared the complaints that prompted the report came from a rival candidate and the party should now apologise to Ms Murphy, who was his office manager, and Mr Deans.

"They have had a terrible few months: They have been staked out by tabloid journalists, had their characters traduced in the newspapers, been attacked by frontbenchers," he said.

Mr Miliband says the overhaul of the process by which union members affiliate to Labour could revitalise the party and boost membership.

But GMB union announced earlier this week that it would cut affiliation fees to Labour by nearly £1m.

Meanwhile, Labour's ruling NEC will draw up a list of potential candidates from which local party members will choose a prospective MP to represent the party at Falkirk in 2015.