Arlene Foster’s failure to secure the support of a majority of MLAs has set a precedent for the Stormont institutions.

The DUP leader is the first politician to hold the first minister’s post but not have the backing of the Assembly.

Yet despite losing a vote of no confidence, the peculiarities of the Stormont system mean she will remain in office.

On Monday, an SDLP motion calling for Mrs. Foster to stand aside for up to six months was defeated because it did not have cross-community support.

However, the motion had 39 votes for and 36 votes against. Sinn Féin did not take part in the vote, though the party has clearly stated that it wants Mrs. Foster to vacate her Stormont Castle office for at least four weeks until the interim findings of a probe into the botched Renewable Heat Incentive are published.

At present, the DUP leader has the support of 35 of her party’s MLAs and justice minister Claire Sugden out of 108 MLAs.

But unless a future no confidence vote secures the support of at least 50 per cent of MLAs who designate themselves unionist or Deputy First Minister Martin McGuinness chooses to leave office, then Mrs Foster will remain the  First Minister.

Ulster University politics lecturer David McCann said the situation the DUP leader found herself in was unprecedented.

“The first minister now operates in an Assembly where only her party and Claire Sugden are willing to vote confidence in her – never has as the first minister operated in a such an environment,” he said.

“The fact that a cross-community vote saved her from being excluded from office for six months does create a narrative of the DUP vs. everybody else. While to most observers, this might seem like a threat to her position, this is comfortable terrain for the DUP, and Foster’s combative performance on Monday demonstrates she is seeking to defiantly face down those who want her to stand aside.”

Sinn Féin said that when the assembly resumes on January 16, it plans to bring a substantive motion calling for Mrs. Foster to step aside while a probe is conducted into the botched Renewable Heat Incentive.