Sinn Fein has accused the DUP of betraying the interests of Northern Ireland by agreeing to prop up Theresa May's minority government through a “confidence and supply” arrangement.

The republican party's leader at Stormont, Michelle O'Neill, predicted the deal between the Tories and the Democratic Unionist Party will “end in tears”.

Northern Ireland has been without a devolved administration for three months following the collapse of power sharing as a result of deep divisions between the DUP and Sinn Fein.

Highlighting Conservative austerity cuts and its stance on Brexit, Ms O'Neill claimed the DUP link-up with Mrs May would spell bad news for Northern Ireland, where a majority of people voted to remain.

“It is no surprise that the DUP has agreed to prop up the pro-Brexit and pro-austerity Tory government of Theresa May,” she said.

“They have once again betrayed the interests of the people of the north by supporting a Tory party which has cut funding to our public services year on year to the tune of hundreds of millions of pounds.

”Experience shows us that unionists have minimal influence on any British government.

“They have achieved little propping up Tory governments in the past and put their own interests before those of the people.

Theresa May reaches 'confidence and supply' deal with DUP

”This new arrangement between the DUP and the Tories will be transitory and will end in tears.

“But it will be the people of the north who will have to pay the price for the DUP's support for Brexit and for cuts.”

Ms O'Neill claimed the Conservatives have an “increasingly partisan approach” to Northern Ireland and called on the Irish government to “stand up for the rights of all citizens in the north”.

She repeated her call for the region to secure special designated EU status when the rest of the UK leaves the 28-state block.

Developments at Westminster could derail talks to restore power sharing at Stormont, which were scheduled to resume on Monday.

Many observers believe the prospect of a deal between the main two parties is further diminished now the DUP has aligned itself with the Conservatives, a party Sinn Fein is historically vociferously opposed to.

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Ms O'Neill said: “Sinn Fein's focus remains on entering talks to re-establish an Executive which delivers for all on the basis of equality, respect and integrity, and this requires the full implementation of agreements on rights and legacy.”

Sinn Fein won seven seats in Northern Ireland at the General Election, but the party has never taken up its seats in Parliament because of its fundamental opposition to the union and its belief in a united Ireland.

Gerry Adams, Sinn Fein's leader, echoed the views of Ms O'Neill ahead of Downing Street's announcement of the confidence and supply arrangement.

"History will show, alliances between Ulster unionism and British unionism has always ended in tears," he said.

"It is far better to look to our own place, to all of the people here, to deal with the people of this island, this part of the island as one community."