Boris Johnson is heading for a showdown with the new president of the European Commission in a clash over post-Brexit trade.
The prime minister is meeting Ursula von der Leyen in Downing Street in their first face-to-face talks since she succeeded Jean-Claude Juncker.
And Mr Johnson will tell the new Commission chief the UK wants a speedy post-Brexit trade deal with the EU, free from rules imposed by Brussels.
The talks coincide with the government's Brexit legislation, the EU Withdrawal Agreement Bill, continuing its swift passage through the Commons this week.
On the first of three days of the Bill's committee stage, the government's new Commons majority of 80 meant all Opposition amendments were heavily defeated.
After the UK leaves the EU on 31 January the PM is facing a race against time as he attempts to negotiate a trade deal before the end of this year.
Mr Johnson has vowed not to extend the so-called Brexit "transition period" beyond 31 December, a promise his critics doubt he will be able to keep.
The Downing Street showdown follows the first Prime Minister's Questions of 2020, at which Brexiteer Tory MPs are likely to urge him to take a tough line with Brussels.
And it comes after Mrs von der Leyen makes a speech at the London School of Economics on the European Union's hopes for a close relationship with the UK after Brexit.
According to No 10, in the Downing Street talks the PM is expected to stress the importance of agreeing a "confident and positive future relationship by the end of December 2020".
"He is expected to tell president Von Der Leyen that, having waited for over three years to get Brexit done, both British and EU citizens rightly expect negotiations on an ambitious free trade agreement (FTA) to conclude on time," No 10 said.
"There will be no extension to the Implementation Period, which will end in December 2020 as set out in the Political Declaration. The Withdrawal Agreement Bill enshrines this in UK law.
"The prime minister will likely underline that the upcoming negotiations will be based on an ambitious FTA, not on alignment."
Downing Street also announced that the Brexit Secretary Stephen Barclay and the EU's Brexit negotiator Michel Barnier will join in for part of the meeting between Mr Johnson and Mrs von der Leyen.
Speaking to Sky News ahead of the talks, Mr Barclay said the PM's meeting with Mrs von der Leyen is an "introductory" one and there was a "shared intent" on both sides to strike a trade deal on time.
