United Kingdom government rules out joint authority in NI

Brexit and the Northern Irish Border

"The principles reflected in this paper must underpin any arrangements and solutions to be proposed, developed and agreed in future negotiations", the statement said. "This will not happen", he said.

The EU, which will have 27 member states after Brexit, wants to solve key exit issues before opening talks about any future trade cooperation with Britain. "It can not preconfigure the future relationship between the European Union and the UK".

But Barnier said: "What I see in the UK's paper on Ireland and Northern Ireland worries me".

London says the issue of how goods and people will move across the frontier can not be separated from discussion about wider customs arrangements between Britain and the European Union. The Commission said that, once sufficient progress has been made in these areas, discussions can move on to the second phase of negotiations, which will include a how to avoid a hard border.

Speaking in Cambridge to the British Irish Association on Saturday night, Mr Coveney said that Britain's proposals for a streamlined customs arrangement appeared to be incompatible with maintaining the integrity of the EU's single market.

London, Dublin and Brussels all agree that the maintenance of an open border, without checks or CCTV cameras, is essential under the Good Friday Agreement.

He has said "a lot more substantial work" was needed on the border issue.

He was expected to say: "In my view the only way of resolving the border conundrum is for Northern Ireland to be within the same customs union and single market as the Republic - either Northern Ireland alone or preferably with the whole of the United Kingdom". "It has to be part of the solution as well, the solution can't come entirely from the European Union", he said.

With slow progress on agreeing Britain's divorce bill, ensuring expatriates' rights and deciding on the Irish border, the European Union doubts it will give a green light in October for starting talks about the post-Brexit order, as had been planned.

The same idea is found in a separate paper on public procurement, in which the European Union insists that public, cross-border contracts launched before Brexit should remain legally protected after the split.

Discussions which have seen the United Kingdom and European Union teams at odds over key issues are "being conducted by people largely talking past each other as if on two separate planets, as different as Mars and Venus", Mr Mandelson said.

Sixty five percent of Enterprise Ireland Client Companies who are not yet exporting to the Eurozone plan to enter the market in the next 12 months.