Theresa May’s DUP allies have delivered a warning shot across the bows after accusing the Prime Minister of breaking fundamental promises on Brexit.
The party joined with Labour to cut the Government’s majority to just five in a Commons vote on the Budget.
They also abstained on a series of other amendments to the Finance Bill on Monday night in a move intended to send a “political message” to Prime Minister.
Their actions appeared to call into question the future of the “confidence and supply” arrangement by which the DUP props up Mrs May’s minority Conservative Government.
Under the terms of the deal, agreed after Mrs May lost her Commons majority in last year’s general election, the Northern Ireland party is supposed to back the Government on Budget matters and on confidence votes.
But DUP Brexit spokesman Sammy Wilson said Mrs May’s deal with Brussels breached a “fundamental” assurance that Northern Ireland would not be separated constitutionally or economically from the rest of the UK.
“We had to do something to show our displeasure,” he told BBC2’s Newsnight.
“She has broken all of those promises – to the people of the United Kingdom, to her own party and to the people of Northern Ireland.”
Shadow cabinet office minister Jon Trickett said the DUP’s withdrawal of support on a Budget measure raised questions as to how long the Government could carry on in the face of widespread opposition to her Brexit deal.
“We no longer have a functioning government. With Brexit only a few months away something has got to give,” he said.
The DUP warning adds to the pressure on the Prime Minister just as a move to unseat her by Tory Brexiteers appeared to have stalled.
Members of the Conservative European Research Group were last week confidently predicting they would get the 48 letters of no confidence needed to trigger a vote in her leadership.
However, there has been no announcement from the chairman of the backbench 1922 Committee, Sir Graham Brady, they have reached that tally while the number of MPs who have publicly declared they submitted letters remains in the twenties.
There were also reports that the so-called “pizza club” group of Cabinet Brexiteers was backing away from a plan to go to the Prime Minister to demand she re-opens negotiations with Brussels on a key element of the agreement.
Michael Gove – who last week turned down the job of Brexit Secretary following the resignation of Dominic Raab – Andrea Leadsom, Penny Mordaunt, Liam Fox and Chris Grayling were all reported to be unhappy with the terms over the Northern Ireland border.
However there was little sign that they were preparing to force a fresh showdown at the weekly meeting of the Cabinet in Downing Street on Tuesday.