SDLP Leader Colum Eastwood MLA has said Christmas will not save the First Minister Arlene Foster from having to stand aside.
The Foyle MLA also accused Sinn Fein of conducting a “disappearing act” during the vote of no confidence he tabled at Stormont on Tuesday.
Mr Eastwood was speaking after the motion, backed by the majority of MLAs at Stormont, fell due to a mechanism which allowed the DUP to block it.
Sinn Fein were not in the chamber for the vote, but Deputy First Minister Martin McGuinness said they will mount a new bid in January to get Arlene Foster to stand aside.
Arlene Foster has delivered a robust defence against claims she should stand down over the Renewable Heating Incentive scandal.
Ms Foster said that she has always worked in the best interests of the people of Northern Ireland and would continue to do so as First Minister.
She also pointed out that the scheme introduced on her watch as Enterprise Minister was endorsed by the Assembly and that no party had picked up on its flaws in its inception.
Speaking after the vote yesterday, Mr Eastwood however said: “As of this moment, Arlene Foster no longer enjoys the support of the Assembly as First Minister.
“The First Minister lost today’s confidence vote, even in spite of a disappearing act from Sinn Féin who talked tough but went missing when it counted.
“Despite saying that Arlene Foster should stand aside, Sinn Féin couldn’t muster a single member to vote to stand her aside. People will cast their own judgment on that particular abdication of responsibility.”
He added: “Over £400m of taxpayer’s money has gone up in smoke. When the budget is presented in January, that will manifest itself in cuts to already stretched public services. This situation is not going away and Christmas will not save the First Minister.
“What is needed now is a judge led public inquiry will full powers to compel evidence and witnesses. The SDLP will now begin to chart an alternative way to hold this government to account.”
Sinn Féin MLA Martin McGuinness meanwhile last night called on the other parties in the Assembly to support a Sinn Féin motion in January calling on Arlene Foster to step aside.
Martin McGuinness said: “Today we have witnessed a shambles in the Assembly, our institutions should not have to endure another day like this.
“The RHI scandal is a massive waste of public funds and the issue will not go away.
“There is a need to restore public confidence in the Assembly and the political institutions.
“Sinn Féin will be bringing forward a motion in early January, which deals comprehensively with the substantive issues surrounding this debacle. The motion includes three key elements.
“First there needs to be a robust time-framed, transparent and independent investigation.
“Secondly we need proposals from the Finance Minister and the Economy Minister to reduce the losses to the public purse from this disastrous scheme.
“And thirdly we believe while this is going on that the First Minister should stand aside during this process.
“It is a strong and reasonable approach and we are calling on the other parties to support our motion in January.”