Northern Ireland secretary James Brokenshire told the Commons the situation at Stormont, following deputy first minister Martin McGuinness’s resignation was “grave” and a snap election was now highly likely.
The departure of Sinn Féin veteran Mr McGuinness amid a row over a green energy scandal forced Democratic Unionist first minister Arlene Foster from office as well.
Theoretically the parties have seven days to resolve their differences before Mr Brokenshire has to call a poll. Mr McGuinness has made clear there will be no going back to the status quo and his party is preparing to face the electorate.
Mr Brokenshire expressed concern about the consequences of an election, raising the spectre of a return to direct rule. He urged the leaders to work together to find a resolution and safeguard the progress made under the peace process.
“We must not put all of this at risk without every effort to resolve differences,” he said. “We must continue to do all we can to continue to build a brighter, more secure Northern Ireland that works for everyone and I therefore urge Northern Ireland’s political leaders to work together to come together to find a way forward from the current position in the best interests of Northern Ireland.”
He said: “We do have to be realistic — the clock is ticking. If there is no resolution an election is inevitable despite the widely held view that this election may deepen divisions and threaten the continuity of the devolved institutions.”
Mr McGuinness’s decision to walk away after 10 years of sharing power with the DUP came as Mrs Foster refused to stand aside to facilitate a probe into the ill-fated Renewable Heat Incentive (RHI) — the so-called cash for ash furore.
The doomed energy scheme has left the administration in Belfast facing a £490m (€563m) bill.
Mrs Foster oversaw the RHI during her time as economy minister. She had repeatedly rejected Sinn Féin’s demands to step down temporarily pending the outcome of a preliminary investigation.
Under the structures of the peace process-forged institutions, neither Stormont’s first minister nor deputy first minister can remain in post without the other, so Mr McGuinness’s resignation spelt the end of Mrs Foster’s tenure.
Mr McGuinness denied that his health problems, for which he is undergoing intensive treatment, had influenced his move.
Stormont finance minister Máirtín Ó Muilleoir accused the DUP of having “spat in the face” of the principles of the Good Friday agreement. He made clear that Sinn Féin would need to gain DUP concessions on a range of issues before contemplating a return to the executive.
DUP ministers would not be “swanning (back) into office, we are not going back to the status quo”, he warned. “The Good Friday agreement has been trampled upon by the DUP, we need to get back to the principles in the Good Friday agreement,” he told RTÉ.
The state-funded RHI was supposed to offer a proportion of the cost businesses had to pay to run eco-friendly boilers, but the subsidy tariffs were set too high and, without a cap, it ended up paying out significantly more than the price of fuel.
This enabled applicants to “burn to earn” — getting free heat and making a profit as they did so. Claims of widespread abuse include a farmer set to pocket £1m in the next two decades for heating an empty shed.