British negotiators will on Wednesday provide the European Commission with a detailed proposal to abolish the Irish backstop following weeks of the demands for hard details from Europe.

The proposal, which was briefed to EU capitals on Tuesday, is a radical departure from the Theresa May deal, which left the entire UK in a customs union with Europe until measures could be developed to ensure an invisible border in Northern Ireland.

Under the new proposals, which have been dubbed “Two borders, for four years," Northern Ireland will leave the EU customs union alongside the UK, but remain aligned on all single market rules for agriculture and industrial goods for four years.

This will create a regulatory border across the Irish Sea between Great Britain and Northern Ireland and a customs border between Northern Ireland and the Republic of Ireland - essentially two borders.

“The proposal means you need to do declarations for goods flowing between Great Britain and Northern Ireland and manage a new border between North and South,” said a source familiar with the proposals. “It leaves Northern Ireland marooned, with frictionless trade with no-one.”