LONDON (Reuters) - Britain on Wednesday said there was no set date for Brexit talks to finish, backtracking from a letter by Brexit secretary Dominic Raab that suggested a deal on the terms of its departure from the European Union could be finalised by Nov. 21.

FILE PHOTO: Britain's Secretary of State for Exiting the European Union Dominic Raab arrives in Downing Street in London, Britain, October 29, 2018. REUTERS/Henry Nicholls

Raab had said that a Brexit deal was firmly in sight and should be agreed by that date in a week-old letter to a lawmaker that was published on Wednesday, briefly sending sterling sharply higher.

But his department later said that while Nov. 21 was the date suggested by the chair of parliament’s Brexit committee, that did not mean a firm date had been set for a deal to be done.

“There is no set date for the (EU) negotiations to conclude,” a ministry spokesperson said in a statement after Raab’s letter to the Chair of parliament’s Committee on Exiting the European Union was published.

“The 21st November was the date offered by the Chair of the Select Committee for (Raab) to give evidence.”

With just five months until Britain is due to exit the European Union, little is clear: Prime Minister Theresa May has yet to clinch a divorce deal and rebels in her Conservative party - both eurosceptic and pro-EU - have threatened to vote down any deal she does make.

Raab, in a letter dated Oct. 24 and sent to Hilary Benn, chairman of parliament’s Brexit committee, said the United Kingdom and EU had resolved most differences, though the issue of Northern Ireland remained.

“I would be happy to give evidence to the Committee when a deal is finalised, and currently expect 21 November to be suitable,” Raab said, in response to a request to appear in front of lawmakers.

“The end is now firmly in sight and, while obstacles remain, it cannot be beyond us to navigate them. We have resolved most of the issues.”

Asked about Raab’s remarks in the letter, a spokesman for May reiterated that Britain wanted to clinch a Brexit deal as soon as possible.

The major obstacle to a deal has been Britain’s wish to keep the border of its province of Northern Ireland with EU member state Ireland open - preserving frictionless trade and a 1998 peace deal that ended Irish sectarian violence - while sticking to its goal of leaving the EU’s single market and customs union so as to forge its own trade deals around the world.

Sterling GBP=D3 surged as much as one percent versus the dollar to trade at $1.2831, and versus the euro to 88.43 pence EURGBP=D3 after Raab's comments, before retreating.

Irish Foreign Minister Simon Coveney said a deal on Britain’s withdrawal was possible by Nov. 21 but that it would require British negotiators in particular to step up efforts.

“I think it is possible to get a deal in November,” Coveney told a joint press conference with French Foreign Minister Jean-Yves Le Drian in Paris.

But Coveney said Britain must make good on its past commitments, including on an open Irish border and a “backstop” clause to anchor it in law, for negotiators to reach an accord.

“If there is no follow through on those commitments, then it is hard to see how this gets done in November,” he said.

British foreign minister Jeremy Hunt said that a deal was “entirely possible” by Nov 21 and that he was encouraged by progress in Brexit talks. He said the outstanding issues could be resolved “if we put our minds to it.”

Raab said four important aspects remained to be resolved: a temporary joint UK-EU customs territory; an option to extend a transition period during which Britain’s EU membership conditions would remain unchanged; a measure to ensure any extension was not indefinite; and continued untrammelled access for Northern Irish businesses to the rest of the United Kingdom.

EU Brexit negotiators told national envoys in Brussels on Wednesday that technical talks were still focussing on the Irish issue. They will give another update next week and the bloc will also hold seminars from mid-November to prepare for a “no-deal” Brexit, a disruptive outcome that both sides say is undesirable.

Sources in Brussels were still hopeful a deal could be sealed in November once Britain has passed its budget.