Jeremy Corbyn is expected to face pressure to clarify his stance on the European Union today after a member of his new shadow cabinet threatened to quit if his new leader backed a ‘Brexit’.

Lord Falconer, Tony Blair’s former flatmate, was seen as a surprise choice by some when he became shadow lord chancellor over the weekend.

Yesterday he suggested that his tenure could be short-lived if the party did not back staying in the EU.

Mr Corbyn told Labour MPs on Monday night that he could not offer David Cameron a blank cheque in his renegotiations with Brussels.

The Prime Minister has pledged to secure a better deal for the UK in Europe ahead of an In/ Out referendum in 2017.

Lord Falconer said: "My view is that we should stay in the EU come what may, so whatever the result of the negotiations.

"I believe that Britain would be so damaged by leaving the European Union or indeed saying we would leave the European Union, that we should stay."

He added: "If the Labour Party adopts a position which says we might leave the EU and might argue against it, then of course my position would become impossible."

Within hours Labour had released a statement from its shadow foreign secretary Hilary Benn saying that Labour had always been committed to "not walking away" from Europe.

The thorny issue of Europe was not the only headache for the new Labour leader, who is expected to make a flying visit to Scotland within days after announcing that next year's Holyrood elections are one of his key priorities.

There was controversy as Mr Corbyn appeared to remain silent during national anthem at a commemoration service to mark the Battle of Britain.

Labour later released a statement insisting that his had been a "respectful silence".

There were also further questions around some of his shadow cabinet choices, including Kerry McCarthy, the vegan new shadow secretary for environment, food and rural affairs.

Mr Corbyn's anti-Trident stance also came under fire from former Labour Defence Secretary and Nato Secretary General Lord Roberston.

He warned: "When the vicious desperados of ISIS are on the march and sabres are rattling across the globe it would be spectacular folly to now end our own deterrent."

Others tried to get the new Labour administration onto the front foot with voters.

New shadow chancellor John McDonnell said that a Corbyn-led Labour government would introduce a £10-an-hour living wage.

Mr McDonnell also appeared to back that Mr Corbyn's stance on the EU saying that Labour would not give the Prime Minister "a free hand on any negotiations".

But Mr Benn later suggested that the party was committed to staying in the EU.

"The truth is if we want to protect workers' rights the answer isn't to leave the EU, but to get rid of this Tory Government," he said.

"That's why the Labour Party has always been committed to not walking away, but staying in to work together for a better Europe.”

Sources said that Mr Benn's comments had been approved by the party leadership.

One Labour MP Simon Danczuk predicted that Mr Corbyn would have to change his tune on the EU.

He said that many Labour MPs were concerned about some of his apparent policy positions, adding: "He has to moderate his policies, whether it is Trident, Nato, the European Union, whatever it might be ..."

He also hit out at the suggestion that Mr Corbyn might wear a pacifist white poppy on Remembrance Sunday.

"I think it is important that he just wears a red poppy," he said.