The health secretary has told Boris Johnson to keep his disagreements over Brexit private, warning that open expressions of dissent could mean a worse deal for the UK.

In one of the strongest public rebuffs to the foreign secretary by a fellow cabinet minister, Jeremy Hunt told Johnson he should maintain collective cabinet responsibility and “work as a team”.

Asked on BBC Radio 4’s Today programme about Johnson’s dismissal of Theresa May’s preferred post-Brexit customs solution as “crazy”, Hunt said this had not been helpful.

“It’s important that we have these debates in private, not just because of collective responsibility – which is what democracy depends on – but also because this is a negotiation,” Hunt said. “And so, on the EU side, if they see divisions in the open, then they will exploit that.”

Asked if Johnson should resign, Hunt said no, but argued that this was, in part, because the foreign secretary was one of the architects of the UK’s decision to leave the EU and should therefore see the process through.

“I think he has a very, very important role to play in government, and he is the architect of the whole Brexit campaign,” Hunt said. “And we are listening to what he said and we are doing what he wants.”

Hunt continued: “But I just think that we also have to recognise we’re not the only people who read the papers, in Britain. They’re read all over the world and we need to give Theresa May some space.

“We’re going to have very lively debates, right the way through until 28 March next year, and probably beyond. But … we should probably have them in private, because that will strengthen Theresa May’s negotiating position.”

Asked whether his message was, in summary, “Boris belt up”, Hunt replied: “You could say that. I’d say he’s a marvellous foreign secretary, let’s work as a team.”

Hunt’s comments come before a cross-party campaign against a hard Brexit launches next week;the former Labour foreign secretary David Miliband, the ex-Lib Dem leader Nick Clegg and the former Tory cabinet minister Nicky Morgan will share a platform at an event next Monday.

Miliband told Today that the trio were getting together because of a “national crisis” over Brexit. “The UK has no negotiating position on the fundamental issues that face the country as it contemplates its Brexit relationship with the European Union,” he said.

With only 120 days to go before a European council meeting at which a deal will be decided, “the truth is that Britain is being held to ransom by the demand for hard Brexit”, said Miliband, who runs an aid charity in New York.

He said there was a strong argument for the UK to stay both in the customs union and the European Economic Area (EEA) after Brexit. He urged Labour to support a Lords amendment passed last week seeking continued UK membership of the EEA.

“The Labour position was not to support that,” Miliband said. “And the warning for Jeremy Corbyn is that if he’s not very careful, he will be the midwife of a hard Brexit that threatens the living standards of the very people that he says he wants to stand up to represent.”

May faces a significant split ahead of a crucial meeting this week of her Brexit inner cabinet over whether to push ahead with a customs partnership, in which the UK would collect tariffs on behalf of the EU in an attempt to minimise the impact on the Irish border, or opt for a so-called maximum facilitation model, which would seek to use technology instead.

Speaking on Radio 4’s Westminster Hour on Sunday, May’s former de facto deputy, Damian Green, suggested one solution might be to go for maximum facilitation but with some sort of extended transition period for it to work.

“I think the most likely endpoint will be some of what’s called the maximum facilitation, some variant of that,” he said. “I, personally, am not yet convinced that you could have that in place by the end of 2020, at the end of the implementation period, and, therefore, you might need to bolt on to that another period, a sort of transition period into that, so that we know not only that it works, but that it works from day one.



It was, Green added, “not the time for members of the cabinet or anyone else inside the Conservative party to indulge in ideology” over such issues.

it had flaws and needed to be tested.