The British pound slid below $1.20 on Tuesday for the first time since the start of 2017, as the UK faces a possible general election amid Brexit turmoil.
Sterling hit $1.1972 around 0640 GMT, as British Prime Minister Boris Johnson faces a rebellion by his own lawmakers over his Brexit strategy that could result in an early general election next month.
The pound later recovered slightly to stand at $1.1987 around 0700 GMT.
"It would appear sterling traders are in no mood to hang around for the result of the votes in parliament, with the pound slipping below 1.20 against the dollar early on Tuesday," Craig Erlam, senior market analyst at Oanda trading group, told AFP.
The vote in the House of Commons is meant to force Johnson to delay Britain's October 31 split from the European Union if he cannot secure better terms with Brussels in the next few weeks.
The prime minister insists instead that Britain will leave the EU with or without a deal on October 31.