The pound has continued to edge lower on currency markets as the government insists that the UK is prepared to leave the EU without a deal.
Sterling fell in overnight trade in Asia to a two-year low of $1.2152 against the dollar.
The currency also lost ground against the euro, falling to €1.0912.
Under new Prime Minister Boris Johnson, the government has toughened its stance on a no-deal Brexit, which it has said is “now a very real prospect”.
The pound – which was trading at $1.50 against the dollar before the EU referendum in June 2016 – has dropped by 2.4% since Monday, when a spokeswoman for Number 10 said that the UK would not enter talks with Europe unless the co-called Irish backstop is scrapped.
She said that because the EU has said it is not willing to renegotiate on this point, “we must assume there will be a no-deal Brexit on 31 October.”
Mr Johnson appeared to strike a slightly softer tone on Monday afternoon, when he said he would “hold out the hand” and “go the extra thousand miles” to strike a new Brexit deal.
However, it was not enough to stop the overnight slide in sterling.
Laura Lambie, senior investment director for Investec Wealth & Investment, warned that the pound could fall further if the UK crashed out of the EU without a deal.
“I do think that investors are looking at a no-deal as a risk, not a certainty,” she said. “That does mean that if we do come out of the EU without a deal, then sterling has further to fall.”