The pound extended losses Wednesday after Boris Johnson's failure to push through his Brexit deal fuelled fresh uncertainty, while Asian markets also ticked lower as investors took a step back after recent gains.
With everything quiet on the China-US trade talks, attention was on Westminster where Britain's prime minister finally got MPs to agree to his EU divorce pact, but minutes later lost a vote on a truncated debate that would have passed it in just three days.
The news means Johnson is unlikely to fulfil his pledge of leaving the European Union the 31 October deadline, and raises the possibility of his calling a general election before the end of the year.
EU chiefs are now expected to recommend another extension to the withdrawal date, which analysts said the PM would blame on opposition lawmakers in the event of a national poll.
The prospect of another delay hit sterling, which fell as low as $1.2843 on Wednesday. The unit had earlier this week broken $1.30 for the first time in five months on hopes of averting a painful no-deal divorce. It was also lower against the euro.
"Getting a revised withdrawal agreement to this point and winning with a convincing margin... is an extraordinary achievement," said Stephen Innes, senior market analyst at AxiTrader.
"But with parliament rejecting PM Johnson's truncated timetable in favour of more time to debate the bill, it now means members will give the statute the fine-tooth comb treatment, opening it to more criticism suggesting it could be knocked down later."
However, one observer pointed out that remarks from Johnson that he would drag Britain out of the EU with the deal come what may could be significant.
"This could be an important, indeed key, shift in the government's position as it may indicate a willingness to extend and then seek to get the bill through Parliament," said Neil Wilson at Markets.com.
"My initial thoughts are that the government will let the EU offer the extension to get the bill through, and (Johnson) can square the circle later with amendments etcetera."
But he added that "the permutations remain nearly endless... Uncertainty prevails, but parliament has backed a deal and that feels like a key moment".
The news weighed on US markets, with all three main indexes ending down, and the losses seeped through to Asia.
Tokyo went into the break slightly lower as investors returned from a one-day holiday, while Shanghai slipped 0.1 per cent and Sydney shed 0.2 per cent.
Hong Kong was down 0.5 per cent, with traders keeping tabs on reactions to a Financial Times report saying China was drawing up a plan to remove the city's beleaguered chief executive after nearly five months of pro-democracy unrest.
Singapore fell 0.6 per cent and Seoul was off 0.3 per cent, while Taipei, Manila and Jakarta were also well into the red.
Wellington tumbled two per cent, with major construction firm Fletcher Building hit by a massive fire at a US$450 million convention centre it is building in the middle of Auckland.
Oil prices dipped after data indicated US stockpiles increased again last week, reinforcing worries about demand as the world economy slows.