The pound rose 0.4% on Friday after three days of declines, trading close to its biggest weekly loss since 2017 after gains last week on the Conservatives' clear election win were erased by the resurfacing risk of a no-deal Brexit.
The pound did not react on Friday after lawmakers, as widely expected, voted by a large margin to pass Prime Minister Boris Johnson's European Union exit deal.
His Withdrawal Agreement Bill is a mixed bag for pound traders. It creates some certainty in that it fixes the EU departure date as Jan. 31, but it revives the risk of a no deal as it bans any extension of a post-Brexit negotiating period scheduled to run to December 2020.
The pound was up 0.4% versus the dollar at $1.3058, having slipped below $1.30 in overnight trading.
Against the euro it was up around 0.8% at 84.88 pence, a move partly explained by euro weakness.
Sterling has fallen around 2% this week, having lost all its election-night gains.
"Johnson is determined to leave the EU and could do that without a trade agreement in place, so this has re-ignited concern about a hard Brexit," said Piotr Matys, an FX strategist at Rabobank.
Chris Graham, senior economist at Standard Chartered, said the fact that Johnson ruled out an extension when under no political pressure to do so caught markets off-guard.
However, some analysts have suggested Johnson could avoid the cliff-edge of December 2020 by rushing through the bare minimum to count as a deal before the deadline, then completing it afterwards.
The pound was little changed by data showing the UK economy grew 0.4% in the third quarter, an upward revision from the previous estimate of 0.3%.
"I think sterling could start to do better again if we see signs of stronger economic data and progress in UK-EU negotiations on the future relationship," Standard Chartered's Graham said.
The Bank of England kept rates steady on Thursday, saying it was too soon to tell how much Johnson's election win would lift the Brexit uncertainty that has clouded the economy.
As expected, Andrew Bailey was announced as the bank's new governor on Friday. Sterling did not move on the news.
George Buckley, chief European economist at Nomura, said Bailey's role went beyond monetary policymaking: "Financial regulation could be a big part of the next year for him, given that there's going to be a lot of debate about any deal (with the EU) that can be had... He's a solid choice."