By Guy Faulconbridge and Andrew MacAskill
LONDON (Reuters) - The European Union's chief Brexit negotiator Michel Barnier told Britain on Monday that the time had come for Britain to make a choice on what sort of relationship it wanted with the bloc after Brexit.
Britain has ruled out staying in any customs union with the EU after Brexit, but the nature of its trading relationship with the world's biggest trading bloc has split Theresa May's government and Conservative Party.
Barnier, speaking after talks in Downing Street with Prime Minister May and Brexit Secretary David Davis, bluntly called on Britain to clarify how it saw the future relationship with the EU after it leaves on March 29, 2019.
"The only thing I can say: without a customs union and outside the single market, barriers to trade and goods and services are unavoidable," Barnier said. "Time has come to make a choice."
"We need also clarity on the UK proposals for the future partnership," Barnier said.
Davis said he was confident he could get agreement on a transition period by the March EU summit.
"Everyone has to play by the same rules during this transition," Barnier said. "The certainty about the transition will only come with the ratification of the withdrawal agreement."
With little more than a year left before Britain's March 2019 exit from the European Union, May's party remains deeply divided over what sort of relationship should be built between the EU and the world's sixth-largest economy.
Such are the divisions within May's government, that the debate over the extent of Britain's possible post-Brexit participation in a EU customs union has taken place in public with key ministers offering a range of views.
Membership of the, or a, customs union after Brexit, would prevent London from striking trade deals with countries outside the EU in future.
"The key point, as the prime minister has said on many, many occasions, is that we need to have our own independent trade policy and be able to strike trade deals with the rest of the world," May's spokesman told reporters.
"We will be leaving the EU and the customs union and it is not government policy to be members of 'the' customs union or 'a' customs union."
(Additional reporting by Kate Holton; Editing by William Schomberg)