Dominic Raab has privately demanded the right to pull Britain out of the EU’s Irish backstop after just three months, the Telegraph has learned, setting back the prospect of clinching a Brexit divorce deal this week.

The hardline pitch by the Brexit Secretary to the Irish government early last week is understood to have “stunned” Irish officials and exposed the continued deep divisions in Cabinet over how to prosecute the Brexit talks.

Mr Raab’s proposal was put to the Irish deputy prime minister Simon Coveney in a private meeting in London last Tuesday, but three days later was apparently contradicted by David Lidington, the UK’s de facto deputy prime minister, on a visit to Dublin.

The divisions emerged as Theresa May’s top Brexit negotiator, Olly Robbins, prepares to go to Brussels to clinch an in-principle Brexit divorce deal this week, triggering an extraordinary EU leaders summit later this month in order to cement the deal.

Reports in the Sunday Times that Mrs May had already concluded a “secret deal” were dismissed to The Telegraph by negotiators from both sides on Sunday night. “If anything, things are now going backwards,” one said.

Mr Raab’s demand that the UK is free to quit the Irish backstop after just three months comes as leading Brexiteers warn that Britain risks being caught in a ‘limbo’ Brexit where the UK is trapped indefinitely in a customs union with the EU.