Tusk 'absolutely sure' EU will accept controversial Brexit draft treaty

"I am absolutely sure that all the essential elements of the draft will be accepted by all," Tusk told business leaders in Brussels, saying EU states would review the text in the coming week.

British Prime Minister Theresa May angrily rejected the draft unveiled on Wednesday, saying she would never allow the bloc to undermine her country's "constitutional integrity".

She took particular aim at a proposal to keep British-ruled Northern Ireland in a customs union if there is no better solution to avoid a hard border with EU-member Ireland.

Tusk said if May didn't like the proposal, she should come up with an alternative.

"Until now, no-one has come up with anything wiser than that (plan)," he said.

"In a few hours I will be asking in London whether the UK government has a better idea, that would be as effective in preventing a hard border between Ireland and Northern Ireland."

Tusk warned that Britain's self-imposed conditions for leaving the EU made "frictionless" trade impossible.

EU President Donald Tusk said Thursday he was "absolutely sure" the bloc's members would accept a draft treaty for Brexit that has stirred anger in London over its provisions for Northern Ireland.

"I am absolutely sure that all the essential elements of the draft will be accepted by all," Tusk told business leaders in Brussels, saying EU states would review the text in the coming week.

British Prime Minister Theresa May angrily rejected the draft unveiled on Wednesday, saying she would never allow the bloc to undermine her country's "constitutional integrity".

She took particular aim at a proposal to keep British-ruled Northern Ireland in a customs union if there is no better solution to avoid a hard border with EU-member Ireland.

Tusk said if May didn't like the proposal, she should come up with an alternative.

"Until now, no-one has come up with anything wiser than that (plan)," he said.

"In a few hours I will be asking in London whether the UK government has a better idea, that would be as effective in preventing a hard border between Ireland and Northern Ireland."

Ireland and the EU have called for any Brexit agreement to avoid a hard border including customs checks, in order to protect the 1998 Good Friday agreement in Northern Ireland, which ended three decades of bloody sectarian violence.

The EU's chief Brexit negotiator Michel Barnier insisted the plan to keep Northern Ireland in the customs union was simply a "fallback" option in case Britain's two preferred options -- hi-tech frictionless border controls, or a solution linked to a future EU-UK trade deal -- both fell through.

But Tusk warned that Britain's self-imposed conditions for leaving the EU -- that it must quit the customs union and single market -- made "frictionless" trade impossible.

"Everyone must be aware that the UK red lines will also determine the shape of our future relationship," the former Polish premier said.

"I want to stress one thing clearly. There can be no frictionless trade outside of the customs union and the single market. Friction is an inevitable side effect of Brexit by nature."

The 120-page draft withdrawal agreement puts into legal text the details of a provisional deal sealed in December by May and European Commission chief Jean-Claude Juncker, which largely fudged the Irish question.

As well as Ireland the paper also covers other issues including the rights of EU citizens living in Britain and the financial settlement Britain will pay as it leaves the EU.