LABOUR divisions over a "rigged purge" of left-wingers taking part in the leadership contest have deepened with Jeremy Corbyn intervening to express his deep concern.

Iain McNicol, the party's general secretary, clashed with the leader's key ally John McDonnell over his claim that some of those backing Mr Corbyn for the Labour crown were being unfairly barred from taking part.

One of the alleged victims of the so-called purge, Ronnie Draper, who leads the 20,000-strong Corbyn-supporting Bakers, Food and Allied Workers Union, has been suspended relating to social media posts, which prevents him from voting in the leadership ballot. He is now taking legal action.

On his campaign visit to Edinburgh, Mr Corbyn entered the fray, saying he was "very concerned" some of his supporters had apparently been "unfairly removed" from the voting list.

"A number of people have contacted me as a result of that and we have sent the names in that we're concerned about to the general secretary and asked him to make sure that the party checks into this carefully to make sure that everyone who is eligible to vote is able to vote in this election. We want a fair and open election," declared the party leader.

Labour’s ruling national executive committee[NEC] has made clear that a "robust validation process" of the almost 650,000 people eligible to vote in the contest will continue until the polls close on September 21. This includes "verifying all voters share the aims and values of the Labour Party".

The party has not commented on the suspension of Mr Draper, which Mr McDonnell said appeared to be "part of a clear pattern of double standards".

The shadow chancellor asked why action had not been taken against Labour peer Lord Sainsbury, who has given the Liberal Democrats more than £2m during the EU referendum campaign or donor Michael Foster over an article referring to "Jeremy Corbyn and his Nazi stormtroopers".

Mr McDonnell said: "Both will, as things stand, be able to vote in this election. Meanwhile, thousands of other members and registered supporters are reported to have been denied a vote without being given an explanation or opportunity to challenge the decision or process.

"Labour party members will not accept what appears to be a rigged purge of Jeremy Corbyn supporters. The conduct of this election must be fair and even-handed," declared the London MP.

He said he would write to Mr McNicol to demand "clear information" on why members were being suspended.

But in response, the Scot tweeted: “John, just to clarify you say 'party officials'. Decisions are made by elected NEC members and not party staff.”

Meantime, Mr Draper said all he had been told was that the disciplinary action was related to an "unidentified tweet" he had posted and he believed the move was arbitrary and politically motivated.

The union leader said, as it stood, he was barred from voting in the leadership election or attending future meetings including next month's party conference.

"I have not been given the opportunity to refute any allegations or a date for any hearing," he explained.

"This flies in the face of natural justice. I intend to challenge my suspension robustly and am currently taking legal advice."

Elsewhere, Mr Corbyn and his colleague Diane Abbott, the shadow health secretary, have made clear the annual party conference, due to take place in Liverpool next month, will go ahead despite a trade union dispute.

A question mark has been hanging over the annual gathering after G4S said it was now too late for it to step in and organise protection arrangements for the four-day conference, which begins on September 25.

The NEC had initially ruled-out G4S for the role but the GMB union then objected to security arrangements being handled by Showsec, the only firm to bid for the contract. It has claimed the firm has refused to recognise the union to negotiate pay and conditions.

Mr Corbyn, campaigning in Scotland, was asked if he accepted the situation looked "messy", to which he replied: "Many things are complicated in life; we'll sort this out. Don't worry about it, conference will take place."

Earlier, Ms Abbott said she “every confidence” that the annual gathering would go ahead.