The pound plunged two percent Friday as Prime Minister Theresa May lost her majority in Britain's general election, fuelling political uncertainty just days before the start of Brexit talks.
May had called the snap vote in a bid to boost her party's hold over Westminster and give her a stronger hand in talks with EU leaders over the country's detachment from the bloc.
However, the leftist Jeremy Corbyn's Labour Party slashed the ruling Conservatives' lead, leaving the country with a hung parliament and political instability for the second time in seven years.
The pound dived from $1.2959 to $1.2674 after it was confirmed the Conservatives had lost their majority. It also sank almost two percent against the euro.
However, London's FTSE 100 opened 0.7 percent higher as the weaker pound helps international firms listed on the index.
Craig Erlam, London-based senior market analyst at OANDA, said: "A hung parliament is the worst outcome from a markets perspective as it creates another layer of uncertainty ahead of the Brexit negotiations and chips away at what is already a short timeline to secure a deal for Britain."
The outcome will throw Britain once again into upheaval less than a year after the country's decision to leave the EU, which led the pound to collapse about 15 percent against the dollar between June and October 2016.
However, Minori Uchida, head of global market research at Bank of Tokyo-Mitsubishi UFJ, told AFP: "May's setback could lead to a soft Brexit, which is not so bad for the British economy in the long run".
While the pound has come under fresh pressure Asian stock markets were mostly higher as traders took the prospect of chaos in Britain in their stride.
Testimony from sacked FBI boss James Comey that Donald Trump asked him to drop a probe into former national security advisor Mike Flynn had little effect.
"James Comey's testimony was pretty forthright and genuinely questioned the president's conduct," said Greg McKenna, chief market strategist at AxiTrader.
"But it didn't appear to have any fresh revelations which could increase the chances of the impeachment of President Trump."
But he added that it was likely to stall the president's agenda to boost growth with tax cuts, big infrastructure spending and deregulation.
Tokyo rose 0.5 percent, Shanghai added 0.3 percent and Singapore gained 0.4 percent while Seoul was up 0.8 percent. Sydney was flat.
However, Hong Kong dipped 0.1 percent a day after ending above 26,000 for the first time in almost two years.
"Even though we're seeing higher sterling volatility, there's even less prospect of that spilling into broader markets," Ray Attrill, head of foreign exchange strategy at National Australia Bank in Sydney, told Bloomberg TV.
"This is still a little local difficulty rather than an event of global proportions."
Paris rose 0.3 percent and Frankfurt was flat.