This is why the DUP might change its mind on Brexit

Analysis: There are indications that the Northern Irish party could ultimately end up supporting Theresa May’s deal, as Benjamin Kentish explains

Will Arlene Foster’s party use its leverage to sweeten the Brexit pill for Northern Ireland? (Reuters)

The DUP‘s opposition to Theresa May‘s Brexit deal is a major problem for the prime minister.

While it only has 10 MPs – a tiny fraction of the 391 that voted against her deal this week – the Northern Irish party’s position is seen as highly significant by many Tory Eurosceptics.

If the prime minister can get the DUP onside, dozens of Conservative MPs may well step into line and back Ms May too.

That is why the government has been deep in negotiations with DUP MPs since the deal was rejected for a second time on Tuesday night.

The talks have mostly involved Geoffrey Cox, the attorney general, and are focused on the issue of the Irish backstop, which would keep the UK in a customs union with the EU if no other way is found to keep the Northern Irish border open after Brexit.

The DUP is vehemently opposed to the backstop because it would see Northern Ireland treated differently in trade terms to the rest of the UK. They fear this is a step towards the breakup of the UK.

Talks are said to be focussed on whether Mr Cox can find a way to change his legal advice to say that there is a way the UK would be able to leave the backstop unilaterally.

The good news for Ms May is that the DUP says it wants to support a deal.

On Thursday, party leader Arlene Foster said: “We are talking to the government and to the attorney general at the moment to try and make a deal happen because we want to see Brexit working, we want to see it working for the whole of the UK in a way that doesn’t leave Northern Ireland behind.”

The prime minister received a further boost on Friday when the DUP’s Westminster leader Nigel Dodds said his party had held “constructive” talks with several government ministers.

He said: “We have had a long series of discussions with a series of cabinet ministers today.

“We have had a constructive dialogue. Those discussions will continue over the coming period of time.”

The bad news for Ms May is that the DUP remains firmly opposed to the backstop, which is a key part of her withdrawal agreement. The EU has repeatedly insisted that it is not willing to reopen negotiations on the deal.

It means that any concessions the government is able to offer the DUP are likely to relate only to Mr Cox’s interpretation of the legal issues around the backstop, not the backstop itself.

The attorney general is reported to be looking at whether the 1969 Vienna Convention on the Law of Treaties – which states that countries can sometimes withdraw from an international treaty if there has been ”a fundamental change of circumstances” – could be used to end the backstop.

Ministers could also try to tempt the DUP into supporting the deal by increasing funding for Northern Ireland. Philip Hammond, the chancellor, joined other cabinet ministers in attending talks with the party on Friday, fuelling speculation that the government could top up the £1bn it gave to Northern Ireland when the DUP agreed to prop up the Conservatives in the Commons.

However, Mr Dodds insisted the party was “not discussing cash in these discussions”.

Asked about Mr Hammond’s presence, he said: “The chancellor of the exchequer is obviously a key member of the government, but he is also responsible for HMRC and the whole issue of their involvement in customs and other regulatory issues is a key concern for us.”

The DUP has said it hopes to find a way to back Ms May’s deal, but whether or not it is able to do so is ultimately likely to come down to Mr Cox’s legal acumen and whether he can somehow find a potential route out of the backstop.

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