David Miliband has warned Jeremy Corbyn that he risks being the “midwife of a hard Brexit” if he orders Labour MPs to oppose remaining in the single market.
The former foreign secretary lined up with senior Tory and Liberal Democrat ex-cabinet ministers in a cross-party push for the UK to keep close ties with Brussels.
In a rare intervention in UK politics, Mr Miliband – who now leads the New York-based International Rescue Committee aid agency – said he was baffled by Mr Corbyn’s opposition to membership of the European Economic Area (EEA).
A Norway-style relationship with Brussels, inside the EEA, would be a “safe harbour” for the UK as it left behind its status as a full European Union member, Mr Miliband suggested.
Dozens of Labour peers rebelled in the House of Lords to support an amendment which would make EEA membership a negotiating objective for the Government.
Mr Miliband suggested that Labour MPs should follow suit even if the party leadership orders them not to support it.
“I am baffled about why the Labour leadership is so worried about supporting the EEA position. I fear the position that they have taken makes Jeremy Corbyn the midwife of a hard Brexit,” he said.
Rejecting the EEA would result in being “driven to a hard Brexit” which impedes trade and undermines employment and environmental standards, he suggested.
“I think there is a real onus on parliamentarians now, when the House of Lords amendment finally comes back to the House of Commons.
“You have seen many Labour peers who know the value of loyalty talking about the essence of doing the right thing this time and my own view is that peers are ahead of the party leadership when it comes to this EEA issue.”
Appearing alongside Mr Miliband was Tory former cabinet minister Nicky Morgan, who indicated she was likely to support the Lords amendment when it comes before MPs.
She added: “If we are not going to get this deep and comprehensive free trade agreement the Prime Minister has talked about, and David Davis has talked about, then the EEA has to be a sensible way to move forward.”
Mr Miliband left the frontline of British politics after defeat at the hands of his brother Ed in the Labour leadership contest in 2010.
There is confusion, contradiction and division where there needs to be cool logicDavid Miliband, ex-foreign secretary
Asked if he had discussed the forthcoming EEA vote with his brother – who is still an MP – Mr Miliband said: “The golden rule that Ed and I have always had is that we work really hard to make sure that our private relationship remains private.”
But he added: “We are certainly in touch, we are in touch on family matters and of course we talk about politics.”
The former foreign secretary expressed dismay at Theresa May’s handling of the Brexit process.
“There is confusion, contradiction and division where there needs to be cool logic.
“There is wishful thinking where there needs to be hard-headed realism and there is tactical manoeuvring when what is needed is strategic clarity.
“A commitment to the hardest of hard Brexits is, in my view, holding the negotiations and the negotiators to ransom.”
The Prime Minister had made a mistake by “lashing herself to the mast of leaving the customs union and single market”, he said.
The only choice left was between “hard Brexit and chaotic Brexit”, he said.
Mr Miliband and Ms Morgan appeared with former deputy prime minister Sir Nick Clegg at rice firm Tilda’s plant in Essex.
The food producer has warned about the impact of Brexit on its business.
They think that the only negotiation that counts is the one between themDavid Miliband
Sir Nick said there was “complete bafflement” from EU leaders and politicians about the UK’s approach.
On the internal Cabinet row over customs, Sir Nick said “we are now debating two models, neither of which are remotely workable or acceptable to the rest of the EU”.
Sir Nick added: “One should never underestimate the narcissism of debate amongst Brexiteers. They think that the only negotiation that counts is the one between them.”
The cross-party alliance renewed speculation about the prospect of a new centrist political movement being formed in the wake of the Brexit vote.
But Mr Miliband denied that was the intention of the move.
“This is about calling for MPs of all parties to stand together,” he told BBC Radio 4’s Today.
“The truth is that Britain is being held to ransom by the demand for hard Brexit, for severing the links with the customs union and the single market that is at the heart of the debate going on at the moment.
“I think that it is significant that people should come together, frankly out of alarm at the prospects for the UK.”