Jeremy Corbyn has almost immediately distanced himself from a loyalty list of Labour MPs apparently drawn up by one of his allies. Labour's candidate for Mayor of London Sadiq Khan, chief whip Rosie Winterton and former Labour leader Ed Miliband were branded 'hostile' in the spreadsheet.

Shadow chancellor John McDonnell, Shadow International Development Secretary Diane Abbott and Jon Trickett were among those reportedly listed in the "core group" category. But a spokesman for Corbyn told IBTimes UK the leader's office had no knowledge of the document. "This doesn't come from the leader's office and we have no knowledge of it," the spokesman said.

The Times, who obtained the list, alleged the Labour leader's political secretary Katy Clark created the document in January but the spokesman denied Clark had any knowledge of the list.

The report in The Times is likely to cause further tension between Corbyn and Labour's parliamentary party. The Labour leader has already faced discontent from his own MPs over his anti-Trident stance as well as recent comments around Britain's sex industry.

The creation of Momentum, a pro-Corbyn pressure group, has also sparked anger among some Labour MPs. But the organisation has denied it is pro-deselection and has stressed it was establishing democratic structures.

The Public and Commercial Services Union (PCS) is also behind a new pro-Corbyn group, Trade Union Momentum.

"It is a crucial moment for Jeremy because it is fairly clear that there are those within Labour and the parliamentary party who do not agree with anything he is doing," PCS General Secretary Mark Serwotka told The Guardian.

"Boundary changes will mean that it is inevitable that there will have to be selections of MPs in a large number of constituencies. There should be no obstacles put in activists' way."