Talks planned in bid to resolve Stormont row
A crunch meeting has been convened to bring Northern Ireland's power-sharing government back from the brink.
The meeting hosted by the British and Irish governments is expected to take place at Stormont House next Tuesday.
In statements released simultaneously, the Northern Ireland Office (NIO) and the Republic's Department of Foreign Affairs (DFA) said the region's political leaders had been invited to review the Stormont House Agreement.
The DFA said: "The failure this week of the Welfare Bill to secure approval in the Northern Ireland Assembly, and the consequent budgetary implications, have a direct and major impact on the prospects for implementing the totality of the Stormont House Agreement.
"Accordingly, following consultation with the British Government, it has been decided that a review and monitoring meeting of the Stormont House Agreement will take place on Tuesday, 2 June."
The NIO said Theresa Villiers had written to party leaders inviting them to take part in next week's meeting at Stormont House - the Northern Ireland Secretary's residence on the Stormont estate.
It is not clear whether First Minister Peter Robinson - who is recovering from a heart attack - will be well enough to attend the meeting.
The Stormont House deal has been widely hailed as finding resolutions to some of Northern Ireland's most intractable problems, including parading and dealing with the legacy of the Troubles.
It was struck two days before Christmas after weeks of negotiations that involved the British, Irish and American governments.
A key plank of the accord to which the five main parties signed up, was the introduction of the Conservative/Lib Dem welfare reforms.
But on Tuesday, Sinn Fein and the SDLP vetoed welfare legislation when it was brought to the floor of the Assembly, plunging the devolved administration into jeopardy.
The crisis deepened even further when Executive ministers failed to agree a budget for next year's public spending yesterday.
Relations between the DUP and Sinn Fein - the two biggest parties at Stormont - have soured since republicans pulled their support for welfare reform in March.
They claimed Executive-funded top-up schemes designed to protect claimants set to lose out under the new benefits system were not as comprehensive as they believed were envisaged in December's negotiations and accused the unionists of acting in "bad faith".
Treasury-imposed penalties for the non-implementation of welfare reforms are currently running at £10 million a month, and the DUP has argued that without change there will be an unsustainable funding gap estimated at around £600 million by the summer.
There have been calls for Westminster to take back welfare powers to break the impasse - a move for which Downing Street has little appetite.
An alternative scenario could see a senior civil servant have to take over responsibility for public finances.
The welfare reform debacle could also have detrimental implications for other elements of the Stormont House accord, including the devolution of corporation tax powers and new measures to deal with the legacy of the region's troubled past.
DUP deputy leader Nigel Dodds said if no resolution can be found, the UK Government must step in.
The North Belfast MP said: "It is not sustainable to have this level of damage caused to our public services by parties because they are not prepared to take practical and sensible financial decisions.
It will result in the collapse of the Assembly by 31st July unless the Government step in and enact welfare reform.
"If some parties in the Assembly will not act then our sovereign Parliament must act."