The European Commission’s new president will make her first official visit to Britain this week, laying the groundwork for the next phase of Brexit talks ahead of the UK’s departure from the union.

Ursula von der Leyen, who replaced Jean-Claude Juncker in December, will meet Boris Johnson at Downing Street on Wednesday – in a reversal of previous visits which have usually seen British prime ministers trek to Brussels for audiences.

The commission president’s visit comes ahead of Britain’s formal exit from the European Union, which is expected on 31 January, pending approval of the Brexit deal by the UK parliament and European parliament.

Ms Von der Leyen is expected to use the meeting to advise Mr Johnson to consider extending the Brexit transition period, which will expire at the end of this year unless the UK decides to extend it.

She warned in an interview with French financial title Les Echos last week that it might be necessary to extend the “extremely short” cliff edge beyond the end of 2020.

“It would be reasonable to evaluate the situation mid-year and then, if necessary, agree on extending the transition period,” she told the newspaper.

But Mr Johnson has announced his intention to write the 31 December transition end date into law, effectively legally binding himself to not extend the period.

Under the withdrawal agreement, the decision on whether to extend has to be made by July, six months from the end of the transition, in order to give both parties time to prepare for a cliff edge.

If no free trade agreement is negotiated then the UK will crash out without a trade deal on WTO terms. Labour has said Mr Johnson should extend the transition period by the maximum two years.

While some issues such as citizens’ rights, the divorce bill and the Irish border will have been solved in the withdrawal agreement struck by Mr Johnson, others will be left hanging at a cliff edge.

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

Even if the UK does manage to negotiate a free trade agreement with the UK, the economic damage to the UK from leaving the single market and customs union is expected to be considerable, according to the government’s own estimates.