Northern Ireland party warns may oppose Brexit deal

The leader of the Northern Irish party that holds the key to British Prime Minister Theresa Mays parliamentary majority warned Tuesday it could yet oppose the Brexit deal she is trying to negotiate.

How to keep the land border open between the British province of Northern Ireland and Ireland after Britain leaves the European Union has become a major sticking point in negotiations.

"There cannot be barriers to trade in the UK internal market, which would damage the economic well-being of Northern Ireland," Foster told reporters after what she called a "useful" meeting.

"We could not support any arrangement that would give rise to customs or regulatory barriers within the UK internal market."

With just a week until a crunch Brexit summit in Brussels at which May is supposed to update EU leaders on progress towards a negotiated divorce from the bloc, all eyes are on the Irish border.

Neither London nor Brussels wishes to see border controls reimposed between Northern Ireland and the independent Irish Republic to its south.

London believes frontier checks will be avoided through a new trade deal with Brussels, but accepts the need for a fall-back plan, or backstop, to address the issue until that deal is agreed.

But Barnier and EU leaders have warned that if London wants land trade with the south to continue unimpeded in the backstop, it will have to accept checks on some goods coming from mainland Great Britain.

After the meeting, Barnier said he had attempted to explain the need for a post-Brexit border plan or "backstop".

"Working hard to explain and de-dramatise the backstop," he tweeted.

Customs union compromise

One possible compromise could see the entirety of the United Kingdom remaining within the EU customs union and single market for goods during an indefinite transition period until a trade deal is agreed.

But hardline "Brexiteers" in May's own Conservative Party could reject a deal that sees Britain caught in a trade limbo, forced to apply EU rules but with no role in setting them.

Barnier's compromise would be for some controls to be imposed on trade across the Irish Sea between Britain and Northern Ireland, so that trade between north and south can remain seamless.

But Foster, while admitting that she had not yet been shown any text on the planned deal by May's government, firmly rejected that.

"The whole point about checks is that it means that there's a difference," she said.

"Why would we need checks between GB and Northern Ireland or between Northern Ireland and GB if we were an integral part of the single market of the United Kingdom?"