Prime Minister Theresa May's Brexit plans are in disarray as her government sought to plot a way around the speaker of parliament's ruling that she had to change her twice-defeated divorce deal to put it to a third vote.
After two-and-a-half years of negotiations with the EU, Brexit remains uncertain.
Options include a long postponement, exiting with May's deal, a economically disruptive exit without a deal or even another EU membership referendum.
Speaker John Bercow blindsided May's office on Monday by ruling the government could put the same Brexit deal to another vote in parliament unless it was substantially different to the ones defeated on January 15 and March 12.
Brexit Secretary Steve Barclay said the ruling meant a vote this week on May's deal was more unlikely but said ministers were studying a way out of the impasse and indicated the government still planed a third vote on May's deal.
"This is a moment of crisis for our country," Barclay said. "The ruling from the speaker has raised the bar and I think that makes it more unlikely the vote will be this week."
"We always said that in terms of bringing a vote back for a third time we would need to see a shift from parliamentarians in terms of the support - I think that still is the case."
May is due at an EU summit in Brussels on Thursday at which she will ask for a delay to Brexit as the British government tries to come up with a way to leave the European Union after 46 years of membership.
EU leaders could hold off making a final decision at that summit on any Brexit delay, depending on what May asks them for, senior diplomats in the bloc said.
Australian Associated Press