Prime Minister Theresa May will ask the European Union to delay Brexit by at least three months after her plan to hold another vote this week on her twice-defeated divorce deal was thrown into disarray by a surprise intervention from the speaker of Parliament.

Nearly three years after Britain voted to leave the EU, its departure is uncertain and European capitals are pressing May to spell out her next moves. Possible eventual outcomes still range from a long postponement, leaving with May's deal, a disruptive exit without a deal, or even another referendum.

Just 10 days before the March 29 exit date that May set two years ago — and two days before a crucial EU summit — she was on Tuesday writing to European Council President Donald Tusk to ask for a delay, her spokesman said.