Theresa May’s battle to save her Brexit deal has suffered a fresh setback after her DUP allies refused to back the Government in series of Commons votes on the Budget.
In one Commons division, the Government’s majority was cut to just five as eight DUPs voted in support of a Labour amendment to the Finance Bill.
The move calls 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 relations have come under intense strain following the publication of Mrs May’s Brexit deal, which the DUP says would undermine Northern Ireland’s position in the United Kingdom.
Labour shadow cabinet office minister Jon Trickett said: “We no longer have a functioning government. With Brexit only a few months away something has got to give.”
As well as voting with Labour on one amendment, the DUP MPs also did not vote on three other amendments.
In a further sign of the Government’s weakness, ministers were forced to offer fresh concessions to stave off a damaging defeat over the publication of the Government’s assessment of the economic impact of Brexit.
Treasury Minister Robert Jenrick told MPs they would now release a comparative analysis of the economic impact if Britain was to remain in the EU rather than leave in March 2019.
Previously, the Government had only undertaken to publish its assessment of the impact of leaving with a deal compared to a no-deal Brexit.
However, it was left facing the prospect of a defeat after a cross-party group of MPs – including Tory Remain supporters Jo Johnson and Anna Soubry – backed a motion calling for a comparison with the status quo.
Labour MP Chuka Umunna, a supporter of the People’s Vote campaign who tabled the motion, said it showed the growing support for a second EU referendum.
“This was the first test of strength facing the People’s Vote campaign in Parliament since the Government published their draft deal, and it is one that we in the campaign have won after gaining support from all sides of the House,” he said.
“The Government was planning to con the British people. It is vital at this crucial time for our country that MPs and the public know the full facts about the cost of Brexit and how it compares to the deal we already have inside the EU.”
Members of the Conservative European Research Group were last week confidently predicting that 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, while the number who have publicly declared they submitted letters remains in the low twenties.