Veteran BBC presenter John Humphrys was accused of representing Boris Johnson during an exchange with the Irish deputy prime minister. 

Simon Coveney said the controversial broadcaster was “speaking for” the arch-Brexiteer as he pressed about the deadlock between Britain and the EU over the Irish border on BBC Radio 4′s Today Programme this morning.

The clash came over Theresa May’s attempt to negotiate a time limit on the so-called backstop, which could see Britain enter a customs union with the EU to avoid the spectre of a hard border in Northern Ireland post-Brexit. 

Coveney, also Ireland’s foreign minister, said Brussels will demand the UK stick to a customs plan “unless and until something better can be agreed”. 

Negotiators are at loggerheads over whether the final fallback option should be that Northern Ireland has different customs arrangements to the rest of the UK – something the prime minister has ruled out. 

Humphrys asked if the EU was willing to set a time limit, to which Coveney replied that May had previously signed up to the “unless and until” form of words.  

But Humphrys countered: “We have moved on from that, that’s what negotiations are about.”

He added: “Nothing is agreed in these circumstances until everything is agreed, as well you know.”

Coveney said “elements of the withdrawal agreement” had “turned green” and the principle of a non-time-limited backstop was one of them. 

He then compared the backstop to home insurance: “You don’t ever expect it to burn down, but you do take out fire insurance and it’s there to reassure people there is a fallback position if everything else fails.”

Coveney then added that the Irish border “goes way beyond economic trade” before Humphrys interjected: “You cannot agree, with the best will in the world, to a system that would effectively keep Northern Ireland in the EU and the rest of Britain out of the EU. You cannot agree to that. You cannot insist on that.” 

Coveney replied: “Well, John, let me please correct you on that, nobody is suggesting that NI stays in the EU.” 

Humphrys said “that would be the effect” of pressing for different customs arrangements, adding: “Certainly an awful lot of people in this country are suggesting [it is], including Boris Johnson and David Davis, and so on, you know who they are. Parliament is deeply divided on this issue.” 

Coveney then told Humphrys: “Johnson doesn’t lead the cabinet. He’s not even in the cabinet.” 

Humphrys said that Johnson “speaks for a very powerful force of public opinion”, before Conveney replied: “Well, John, you sound like you’re speaking for him.” 

Humphrys said “there are a lot of views” and “Ireland has to respect those views as well”. 

It comes as Theresa May prepares to head out to Brussels for dinner with EU leaders ahead of a council summit. 

It was reported in the Times last night that Emmanuel Macron is ready to call for the immediate resumption of Brexit talks after the summit, and could be willing to push for a time limit on the backstop.  

Coveney added that “nobody is asking that Northern Ireland remain part of the EU” or “threatening the sovereignty of the UK” but stressed that the principles of the Good Friday Agreement, which secured peace in Northern Ireland after the Troubles, requires consent. 

He said the GFA had offered “stability and normality” and an “absence of violence” and May had a “responsibility” to avoid “collateral damage” during the Brexit process. 

“We are not trying to do anything else except protect that peace process,” he said.  

Coveney also slammed “inaccurate, macho talk” about countries being able to survive a no-deal Brexit.