Just a week before the deadline, Britain and the European Union struck a free-trade deal Thursday that should avert economic chaos on New Year's and bring a measure of certainty for businesses after years of Brexit turmoil.

British negotiators arrived in Brussels on Sunday for what is potentially the final attempt to strike a deal with the European Union over future trade ties, even though “significant differences remain” on three essential points.

British Prime Minister Boris Johnson is setting out a tough opening gambit Monday in negotiations with the European Union, saying the U.K. will walk away without a free-trade deal rather than agree to follow rules set by the 27-nation bloc.

Britain might face huge challenges in external trade talks even if it could take control of the trade policy after Brexit, experts warned at the second UK Trade Policy Observatory (UKTPO) conference in London Wednesday.