DOWNING Street has raised the possibility that any nomination by Jeremy Corbyn to make John Bercow, the former Commons Speaker, could be blocked because it would break convention.

The Prime Minister’s spokesman, responding to weekend reports that the Labour leader had nominated Mr Bercow in the so-called Dissolution Honours List, pointed out that by “long-standing convention” the Labour leader could only nominate members of his own party.

This raises two possibilities; either the ex-Speaker, a Tory, has recently become a member of the Labour Party, or Mr Corbyn is determined to defy convention.

Labour has not denied reports that Mr Bercow - regarded by some Tory Eurosceptics as being biased during the Brexit process - is among the list of nominees for peerages drawn up by Mr Corbyn.

Normally, former Speakers are nominated for a peerage by the sitting Government; the fact that this has not been raised this time around suggests a deal or resentment exists over Mr Bercow's time in the chair by UK Conservative ministers.

The former Speaker, who stood down from his role ahead of the General Election, was elected as Tory MP for Buckingham before becoming Speaker in 2009.

Downing Street would not comment on specific nominations and it is understood that no list of potential peers from Mr Corbyn has so far been submitted to Boris Johnson.

But his spokesman explained: "It is a long-standing convention that Leaders of the Opposition can nominate individuals representing their party for peerages."

Mr Bercow is not the only controversial choice reportedly on Mr Corbyn's list of nominations.

His former chief of staff, Scot Karie Murphy, has also been put forward for an honour despite the current inquiry into alleged instances of anti-Semitism in the Labour Party by the Equality and Human Rights Commission [EHRC].

The Jewish Labour Movement said Ms Murphy's nomination was "deeply inappropriate and must be rescinded immediately".

It said: "Jeremy Corbyn is using his final weeks in office to reward failure."

Campaign group Hope Not Hate stressed: "No-one who is a subject in the EHRC investigation should be ennobled before the full EHRC report is released."

This view was echoed by Rosena Allin-Khan, Labour deputy leadership hopeful, who said: "Hope Not Hate said that anyone who was being investigated by the EHRC shouldn't be recommended for a peerage, so I do think that does need to be taken seriously."

Senior Labour sources have declined to comment on reports about the nominations.