The row between Sir Richard Branson and Jeremy Corbyn has deepened as the Labour leader's most senior ally called for the Virgin boss to have his knighthood taken.

Shadow chancellor John McDonnell attacked the business tycoon, saying he wanted to "undermine our democracy" after Virgin Trains released footage disputing Mr Corbyn's claims about overcrowding on its services.

Mr McDonnell, who is running Mr Corbyn's campaign to be re-elected as leader of the Labour party, demanded an overhaul of the honours system, and also reiterated that former BHS boss Sir Philip Green should lose his title.

Writing in the Sunday Mirror, Mr McDonnell said Sir Richard was a "tax exile who thinks he can try and intervene and undermine our democracy".

The feud between Mr Corbyn and Sir Richard began after Virgin Trains releasedCCTV images showing contradictory evidence to the Labour leader's claims about overcrowded train carriages.

Mr McDonnell said: "The whole purpose of the honours system is undermined when the rich and the powerful can collect their gongs without giving anything back. It's even worse when tax exiles are given honours."

He added: "It should be a simple choice for the mega-rich. Run off to tax exile if you want. But you leave your titles and your honours behind when you go."

A spokesman for the shadow chancellor said: "John believes that it should be for Parliament to ultimately decide who is or who is not stripped of their title, if enough members of the public campaign for it.

"But he would not support tax exiles or businessmen who mistreat their employees retaining their titles."