LONDON (AFP) - The EU's chief Brexit negotiator Michel Barnier on Monday (Feb 5) warned trade barriers were "unavoidable" for Britain once it leaves the EU if it also quits the single market and customs union as planned.

"Without customs union and outside the single market, barriers to trade in goods and services are unavoidable. Time has come to make a choice," Barnier said after talks with Brexit minister David Davis in London.

Barnier also said the EU would consider a transition period for Britain after it leaves the bloc that would allow for continued temporary access to the single market and customs union to allow businesses to adapt.

But he added: "The conditions are clear, very clear.

"Everyone has to play by the same rules during this transition," he said after the Downing Street meeting.

Davis said he was "confident" an agreement could be reached on the transition period by March this year.

He said he wanted a "frictionless" trade deal with the EU, following days of pressure from pro-Brexit MPs for the government to rule out any customs union with the EU.

Hardliners warn that a customs arrangement could hamper Britain concluding trade deals with other countries.

Barnier concluded: "We need... clarity about the UK proposals on the future partnership."

"We wait for an official position from the UK government in the next weeks," he said.