The UK’s access to the single market will be weakened if it does not continue to sign up to EU rules after Brexit, Ursula von der Leyen has said.

Speaking at the World Economic Forum in Davos, the European Commission’s president warned of “more distance” between the UK and EU if such a state of affairs came about.

She also insisted that trade talks would begin in February, following speculation that there could be a further delay until March.

Her comments came as the chancellor, Sajid Javid, said there was “no point” in leaving the EU unless the UK was going to ditch the Brussels rule book.

Ms Von der Leyen’s said that the “next negotiations will start in February with our British friends” and said officials would “work day and night” to reach a deal.

The prime minister, Boris Johnson, has set himself a deadline of reaching a trade deal by the end of the transition period in December. If one is not secured by that point, UK firms will face tariffs and quotas that could wreck their businesses.

“The closer the UK is to the European Union, the better the access to the single market,” Ms Von der Leyen told the conference.

“If it is the UK’s choice not to do so, to be more distant to the European Union, well, then there will be more distance to the single market where the level playing field is concerned and where free movement of goods, capital and services is concerned.”

Mr Javid, who was also speaking at the conference, said a deal could “absolutely” be agreed by 31 December.

“There is a strong belief on both sides it can be done,” he said.

Bizarre: Boris Johnson drives 'Brexit' digger through boxes Show all 8 1 /8 Bizarre: Boris Johnson drives 'Brexit' digger through boxes Bizarre: Boris Johnson drives 'Brexit' digger through boxes Conservative party leader Boris Johnson drives a JCB through a fake wall POOL/AFP via Getty Images Bizarre: Boris Johnson drives 'Brexit' digger through boxes Prime Minister Boris Johnson during a visit to JCB cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty Bizarre: Boris Johnson drives 'Brexit' digger through boxes Prime Minister Boris Johnson sits in a cab of a JCB during a visit to its cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Britain, December 10, 2019. Ben Stansall/AFP/Pool via REUTERS POOL REUTERS Bizarre: Boris Johnson drives 'Brexit' digger through boxes A sign made for a visit by Prime Minister Boris Johnson to the JCB cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson reacts as he sits in the cab of a drives a Union flag-themed JCB, after driving through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty

“Both sides recognise, of course, that it’s a tight timetable, a lot needs to be put together in the time that we have, but it can be done and it can be done for both goods – where we want to see free trade, zero tariffs, zero quotas – but also on services.”