Johnson's Brexit plan comes under attack from Westminster, Dublin and Brussels

The backstop is the insurance policy demanded by Brussels to ensure no hard frontier is created on the island of Ireland.

In response, Arlene Foster, leader of Northern Ireland's main party, the Democratic Unionist Party (DUP) hit out at Dublin's stance.

She said: "Mr Coveney's rejection of a reasonable offer is paving the road for a no-deal exit because unionism will not allow Northern Ireland to be trapped at the whim of Dublin or the EU. We will not buy that."

Political commentators in Britain say the new proposals have a better chance than former British prime minister Theresa May's Brexit deal of winning the backing of the House of Commons.

But a tougher task for Johnson is winning the approval of Brussels and each of the 27 EU members, including Ireland.