By David Young, Press Association
The UK Government has appealed to Northern Ireland's political leaders to step back from the brink of the current political crisis.
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 Fein 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.
However, 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."
The Secretary of State's comments came after a senior Democratic Unionist predicted that Northern Ireland faced a prolonged period of direct rule from Westminster.
Jeffrey Donaldson said the bitter political row between his party and Sinn Fein was unlikely to be resolved without a lengthy talks process following the looming snap election.
The DUP MP also questioned whether the existing mandatory coalition power-sharing arrangements could ever be revived, and said his party could now press for major reform and the introduction of a system of voluntary coalition.
"My own sense of where we are is that we are looking at a prolonged period of direct rule because I don't see these issues being resolved in a talks process in a short space of time," he said.
"I think that Sinn Fein have dealt a serious blow to power-sharing and I think the prospect of a mandatory coalition being restored has been greatly diminished, so if we are going to have another talks process then I think unionists will want to be looking at how Stormont operates and whether we should be moving towards our objective of a voluntary coalition form of government."
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 £490 million bill.
DUP leader Mrs. Foster oversaw the RHI during her time as economy minister.
She had repeatedly rejected Sinn Fein'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 current tenure in the job.
Mr. McGuinness denied that his health problems, for which he is undergoing intensive treatment, had influenced his move.
Stormont Finance Minister Mairtin O Muilleoir accused the DUP of having "spat in the face" of the principles of the 1998 Good Friday Agreement peace accord.
He made clear that Sinn Fein 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," Mr. O Muilleoir told RTE.
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 allegedly set to pocket around £1 million in the next two decades for heating an empty shed.
While the DUP and Sinn Fein were in agreement on the terms of a potential investigation into the RHI, the sticking point was the position of Mrs. Foster when the probe got under way.
Steps by the Executive to cut the costs of the overspend will not be implemented in the short term.
Mr. McGuinness cited other disputes with the DUP, including over the Irish language and stalled mechanisms to deal with the legacy of the Troubles, in explaining his move.
It is clear that all those issues, and other unresolved rows, would need to be addressed before a new executive could be formed.