Jo Johnson, the younger brother of Boris, has resigned from British Prime Minister Theresa May's government, calling in a withering critique for another referendum to avoid the vassalage or chaos that he said her Brexit plans would unleash.
Quitting as a junior transport minister, Johnson called May's Brexit plans delusional and said he could not vote for the deal she is expected to unveil in parliament within weeks.
"Britain stands on the brink of the greatest crisis since the Second World War," said Johnson, a former Financial Times journalist who voted to stay in the EU in the 2016 referendum.
Johnson, 46, called it the worst failure of statecraft since the 1956 Suez canal crisis, in which Britain was humiliatingly forced by the US to withdraw its troops from Egypt.
"To present the nation with a choice between two deeply unattractive outcomes, vassalage and chaos, is a failure of British statecraft on a scale unseen since the Suez crisis," he said on Friday.
"Given that the reality of Brexit has turned out to be so far from what was once promised, the democratic thing to do is to give the public the final say," he added.
Johnson's criticism underscored the travails that May faces in getting any Brexit divorce deal, which London and Brussels say is 95 per cent done, approved by her own fractious party.
At the same time Ireland's Prime Minister Leo Varadkar said a deal between Britain and the EU was possible in weeks despite continued political haggling over the future of the border between Ireland and Northern Ireland.
"A successful outcome is not guaranteed but I think it is possible in the next couple of weeks," Varadkar said at the British Irish council on Friday.
Less than five months before Britain is due to leave the EU on March 29, negotiators are still haggling over a backup plan for the land border between British-ruled Northern Ireland and EU member Ireland should they fail to clinch a deal.
The DUP, the Northern Irish party on whose parliamentary votes May relies to keep her in power, cast her Brexit negotiation as a betrayal earlier on Friday because it believes it could allow Northern Ireland to be separated from the UK.
Varadkar said that while the DUP was important, there were other voices in Northern Ireland.
"When it comes to Northern Ireland, it's very important to listen to, and have regard for, what the DUP has to say, but there are other political parties as well," he told reporters.
The Irish government did not want to see any new borders between Ireland and Northern Ireland, he said, and that the point of the backstop, which in some forms the DUP opposes as it could lead to the separation of the UK and Northern Ireland, was to protect an open border.
Meanwhile EU negotiators have told national envoys that they need more work yet to close a Brexit deal, diplomats familiar with the briefing told Reuters.
One described the update on the state of play be members of European Commission negotiator Michel Barnier's team as "sober" and free of "drama". "More talks to be had," summed up another.
Both sides have closed in on a deal but remain deadlocked over clauses aimed at avoiding disruption on the Irish border -- an issue that is dividing May's government and jeopardising her ability to get any agreement through the British parliament.