Talks on a post-Brexit trade deal between the UK and EU will begin in February, European Commission president Ursula von der Leyen has said.

The commission previously warned that it could be March before the 27 EU member states had agreed their approach to the talks.

Speaking at the World Economic Forum in Davos, Ms von der Leyen restated her position that the UK’s access to the single market would be weakened if it diverged from Brussels’ rules.

But Chancellor Sajid Javid, who was also at the Swiss ski resort, said there was “no point” in leaving the EU unless the UK was going to move away from the Brussels rulebook.

Boris Johnson, during an online “people’s PMQs” session, said he wanted an “all-singing, all-dancing” free trade deal.

In a move to reassure Brussels, he insisted the UK would not engage in “dumping” by lowering social or environmental standards once outside the EU’s regulations.

“We are going to set benchmarks for high standards in the UK and around the world, I believe that will be a good basis to do a fantastic free-trade deal,” he said.

The commission president said the “next negotiations will start in February with our British friends” and promised that officials would “work day and night” to reach a deal.

A trade deal needs to be in place when the transition period expires at the end of the year as the UK Government has ruled out extending the process.

Ms von der Leyen said: “The closer the UK is to the European Union, the better the access to the single market.

“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 said a deal could “absolutely” be agreed by December 31.

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

“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.”

Business groups have raised concerns about the prospect of divergence from the single market, but Mr Javid defended the approach.

“Brexit will be a change,” he said. “We’ve had this relationship with the EU, a lot of economic integration for over 40 years, and of course as we leave there’s bound to be change.

“But we’ve also been clear that there is no point in leaving the EU and then sticking with all its rules and regulations forever.

“We are leaving the EU which means we are leaving the single market, we are leaving its customs union, that does mean we will not be a ruletaker.”