The Conservatives have suffered a climbdown over health service pay caps after the DUP backed Labour at Westminster.
Senior Democratic Unionist Ian Paisley said it sent out a “clarion call” on the issue of higher wages for doctors and nurses.
MPs supported a non-binding Opposition House of Commons motion calling for an end to the public sector pay cap in the NHS but it was not put to a vote after the Government did not contest it.
Mr Paisley is one of 10 pro-Brexit DUP MPs helping to prop up Prime Minister Theresa May’s Tory administration after her snap election left her with no overall majority.
Wednesday would have marked the first time DUP MPs voted to pressure ministers since their party agreed to a confidence and supply arrangement with the Conservatives after the general election.
Because the motion was not binding it would not have amounted to a breach of the £1 billion Tory/DUP deal.
North Antrim MP Mr Paisley said: “I’ve already alluded to the fact that I’m delighted that the Labour Party has brought forward this debate tonight.
“We will support them if this matter goes to a vote tonight, and it’s interesting to see if we will actually get to that point.
“Maybe the House will agree that the points that have been raised today are such that we should send out a clarion call from this House that we do agree with the points that have been raised, all across this chamber today.”
The Government only commands a majority because of its confidence and supply arrangement with the DUP, which has said it will support the Conservatives on key legislation.
Mr Paisley added: “To those members of the Labour Party who chide about the £1 billion deal, your party would quite happily have cut a deal that would probably have been better for us.
“That’s the discussions we had in advance of the last election, and to chide us, you only hurt public servants in Northern Ireland who are benefiting from that £1 billion deal that will allow us to allocate this money to relieve these costs.”
DUP deputy leader Nigel Dodds said the motion was not covered by the confidence and supply arrangement agreed by the two parties.
“Lifting the cap on nurses’ pay and in the public sector generally is our party policy. The Government understood that is the way that we were going to vote,” Mr Dodds told Sky News following the debate.
“It is not part of the confidence and supply arrangements. We are separate parties, we are not part of the Government and we will make up our own mind on those issues.”
Conservative sources insisted they were “pretty relaxed” about the outcome of the debate, which does not require the Government to change policy.
It comes the day after ministers effectively ended the pay cap with the announcement of rises above the 1% limit for police and prison officers.
Ahead of the vote, DUP deputy leader Nigel Dodds also signalled his party’s support for Labour.
“The DUP wants to see fair pay for public sector workers,” he said. “We have consistently argued against the pay cap therefore will be voting for the motion in the House of Commons today.
“Whilst others chased headlines and engaged in House of Commons stunts during the Queen’s Speech debate, the DUP has sought to ensure public servants throughout the United Kingdom get a fair deal.
“We welcome the Prime Minister’s commitment to flexibility on the pay cap. At the General Election, the Government received a clear message about austerity. The Chancellor has said he is “not deaf” to the voice of the electorate.
“Having delivered hundreds of millions of extra pounds for health, education and public services through our deal with the Government, we will continue to deliver on other key objectives both for Northern Ireland and for the United Kingdom as a whole.”
The DUP also sided with Labour on a second successful motion against the Tories, according to a string of press sources.
A bid to scrap regulations which allow universities to raise fees up to £9,250 was approved unopposed after no MPs voiced opposition when asked by the deputy speaker.
The motion represented a symbolic defeat but prevented the government from suffering the embarrassment of seeing their DUP allies walking through the lobbies in support of Labour.
Conservatives say the terms of the confidence and supply deal with the DUP does not cover non-binding opposition motions, with Tory MPs not whipped to turn up to vote.
No DUP MPs were in the chamber for the start of the debate however two were present at the time of the vote, and a DUP source said all 10 were nearby “had it come to a vote”.