The chairman of European Union leaders Donald Tusk and Irish Prime Minister Leo Varadkar agreed they must see what proposals emerge from London in advance of Thursday's meeting of EU leaders, a spokesman for Varadkar said on Tuesday.

 Tusk was in Dublin to meet Varadkar as the British government's Brexit plans fell into further disarray, and he expressed EU leaders' strong and ongoing solidarity with Ireland in negotiations, the spokesman said in a statement.

"Meanwhile, preparations continue in Ireland and across the European Union for a no-deal scenario, which would have serious consequences for all concerned," the statement added.