Speaking to Ireland's RTE radio, EU Financial Services Commissioner Mairead McGuinness said: "If the priority is simply to appease hardliners in Johnson's Conservative Party, I think we are in a very bad place. "If people in London are of the view that there will be no compromise, then there will be no progress and that's untenable."

       Ms McGuinness said she was anticipating "some instability" in Protocol talks as a result of the departure of Lord Frost.

       However, also speaking to RTE Radio on Sunday, Public Expenditure Minister Michael McGrath said the Irish government does not expect the resignation of British Brexit minister David Frost to delay progress in talks on the Northern Ireland trade rules as he was just representing the views of the British government.

       Mr McGrath said: "We expect that it shouldn't delay the progress that has been made.

       "From our perspective and from the European Union's perspective, he was in the room negotiating on behalf of the British government."

       Llord Frost's resignation letter, widely circulated yesterday, cited concerns over the Government’s “direction of travel”, especially in relation to tighter coronavirus restrictions.

       He wrote: "You took a brave decision in July, against considerable opposition, to open up the country again.

       "Sadly it did not prove to be irreversible, as I wished, and believe you did too.

       “I hope we can get back on track soon and not be tempted by the kind of coercive measures we have seen elsewhere."

       (More to follow)