Boris Johnson is expected to open talks on the country’s post-Brexit trade deal with the new president of the European commission when she visits Downing Street next week.

The prime minister will meet Ursula von der Leyen on Wednesday for the first time since she took up her post, three weeks before Britain’s departure from the EU on 31 January.

Von der Leyen suggested last month that Johnson should reconsider his refusal to extend the 11-month timeframe available for agreeing a deal on the UK’s future relationship with the EU after Brexit.

During the post-Brexit transition, Britain will remain in the bloc’s customs union and single market, meaning it continues to trade under EU rules, until the end of 2020.

Johnson has ruled out the option of maintaining those arrangements for a further two years. He claims there is enough time to negotiate a deal with the EU covering issues including trade, internal security, transport and data sharing.

Comprehensive trade deals between the EU and countries such as Canada, Japan and Singapore have previously taken between six and eight years to agree.

Britain’s withdrawal agreement allows for a prolongation of the transition period to be negotiated by 1 July. If no trade deal is in place by the end of 2020 and there is no extension, the UK faces major disruption to its economy with tariffs and quantity restrictions immediately applied to goods sold into the single market.

Von der Leyen, a former German defence minister, said last month in an interview with French newspaper Les Echos: “It’s not only about negotiating a free trade deal but many other subjects. It seems to me that on both sides we must ask ourselves seriously if all these negotiations are feasible in such a short time.

“I believe that it would be reasonable to review things in the middle of the year, if necessary to see if an extension is needed.”

Von der Leyen took up her post last month as president of the European commission, the EU body responsible for drafting and enforcing laws for member bodies, succeeding Jean-Claude Juncker. As well as meeting Johnson next week, she will also give a speech at the London School of Economics during her visit.