The EU's chief Brexit negotiator has warned Britain "the time has come to make a choice" as he warned of "unavoidable" trade barriers.

In a visit to Downing Street on Monday, Michel Barnier outlined a robust stance over the impact on trade in goods and services if the UK leaves the single market and customs union.

It follows a recent bout of infighting within the Conservative Party over whether or not Britain should retain a customs union with the EU beyond 2019.

Tory Brexiteers have expressed fears remaining in a customs union with the EU after Brexit will hinder the UK's ability to sign independent trade deals with countries outside the bloc.

But pro-Remain Conservatives have cautioned the "only way" to achieve the Prime Minister's aim of "frictionless" trade between the UK and the EU is to remain in the customs union.


Speaking alongside Brexit Secretary David Davis in Number 10, Mr Barnier said: "We need clarity about the UK proposals for the future partnership.

"The only thing I can say, without a customs union and outside the single market, barriers to trade in goods and services are unavoidable.

"The time has come to make a choice."

Image: The EU official and Brexit Secretary David Davis held talks over lunch

Mr Barnier also held a 20-minute meeting with the Prime Minister on Monday, before his lunch with Mr Davis.

On Wednesday and Thursday, Theresa May will chair two meetings of a key Cabinet sub-committee to thrash out the UK's approach to the next phase of Brexit negotiations.

Asked whether the Conservative Party will ever agree on an approach to Brexit, Mr Davis insisted the Government's ambition was "perfectly clear".

"We've said in terms we want a comprehensive free trade agreement and with it a customs agreement," he said.

"And to make that as frictionless as possible. To make as much trade that currently exists as free as possible whilst still giving ourselves the opportunity to make free trade deals with the rest of the world."

Mr Davis earlier stressed a "time-limited" transition period after 2019 would "lead to us being outside the customs union and indeed the single market in the longer term".

The Brexit Secretary hailed Monday's "very constructive conversations" and revealed UK and EU officials will begin "intensive" talks on agreeing the terms of a transition deal from Tuesday.

Mr Davis said he was "confident" such an agreement will be struck by the time of the European Council summit in March.

Image: Theresa May will hold crunch Cabinet meetings on Brexit this week

Declaring the EU will "not give a running commentary" on Britain's domestic debates over Brexit, Mr Barnier expressed his hope the UK Government will "clarify" it's position on a future UK-EU relationship "in the next few weeks".

The European Commission official claimed there is still "some work to do" on finalising the UK's "orderly withdrawal" from the EU, on which a draft agreement was agreed before Christmas to allow Britain to move on to talks about a transition period and a future trade deal.

In response to Mr Barnier's warning of post-Brexit trade barriers, the Prime Minister's official spokesman said: "We have said that we want the customs arrangement to be as frictionless as possible and that's what we will be looking to achieve as part of the deep and special partnership that we are seeking with the EU.

"We want it to be as frictionless as possible and we think we can achieve that because it's in the interests of the UK and the EU. As with all these matters, it's the beginning of a negotiation."

Mr Barnier later met with Labour leader Jeremy Corbyn, shadow Brexit secretary Sir Keir Starmer and shadow foreign secretary Emily Thornberry.

PM: UK will leave Customs Union and negotiate free-trade deal

Last week, a row broke out after leading Brexiteer Jacob Rees-Mogg, who leads an influential group of Tory MPs, accused the Treasury of "fiddling the figures" in Brexit forecasts with the aim of keeping Britain in the customs union.

Mr Rees-Mogg stepped up his attack on Monday, as he appeared to blame Chancellor Philip Hammond - who has repeatedly been accused of agitating for a "softer" Brexit - for the "biased" forecasts.

In the House of Lords, peers compared Brexiteers' attacks on civil servants to US President Donald Trump's ongoing feud with the FBI.

Meanwhile, prominent europhile Tory MP Anna Soubry warned the "only way" to preserve frictionless trade with the EU is to remain in the customs union.

She also used her Twitter account to "gently remind" her Conservative colleagues the Government had lost its majority in the House of Commons last June, which she attributed to voters having "rejected" a "hard Brexit" outside the customs union.