UK MPs take no-deal Brexit off the table

British MPs have rejected leaving the European Union without a deal in any scenario, paving the way for a vote to delay Brexit to seek a way out of the country's worst political crisis in generations.

MPs on Wednesday voted by 321 to 278 in favour of a motion that ruled out a potentially disorderly no-deal Brexit under any circumstances.

It went further than the government's own planned motion, which noted that parliament did not want to leave without a deal on March 29, the leaving date set down in law, but stressed that the default legal position was to leave without a deal unless one was ratified by parliament.

The approved motion has no legal force and ultimately may not prevent a no-deal exit after a possible delay, but it carries considerable political force, especially as it demonstrated a substantial rebellion by members of May's own party.

After two-and-a-half years of negotiations and two failed attempts to pass a Brexit deal proposed by May, the vote against a no-deal exit still leaves undecided how, when and on what terms Britain will leave the club it joined in 1973.

After MPs crushed her deal for a second time on Tuesday, May said it was still the best option for leaving in an orderly fashion.

The pound spiked to the day's high and was headed for its biggest daily gain in 2019.

As the United Kingdom's three-year Brexit crisis spins towards its finale, diplomats and investors see four main options: a delay, May's deal passing at the last minute, an accidental no-deal exit or another referendum.

If Britain does seek a delay, it will require the agreement of all the bloc's other 27 members.

The EU would prefer only a short extension, with the deadline of EU-wide parliamentary elections due on May 24-26, although it is unclear that this would be long enough to solve the impasse in London.

EU Brexit negotiator Michel Barnier said the bloc would need to know why Britain wanted to extend talks and that it was up to London to find a way out of the deadlock. The EU said there could be no more negotiations on the divorce terms.

As Brexit uncertainty spills into financial markets across the world, investment banks such as Goldman Sachs and JPMorgan are offering different probabilities on the outcomes.

"We continue to see a 55 per cent chance that a close variant of the prime minister's Brexit deal is eventually ratified, after a three-month extension of Article 50," Goldman said.

It gave a reversal of Brexit a 35 per cent probability and a no-deal Brexit 10 per cent.