Northern Ireland's power-sharing government failed to pass a social welfare bill on Tuesday that several senior figures have said could lead to the collapse of the regional assembly in the British-controlled province.A deal struck between the Northern Ireland parties and the British Government late last year was supposed to have eased the way for welfare reforms by promising the local administration a package including loans which would have helped mitigate the cuts enacted in other parts of the United Kingdom.However the social welfare reforms, submitted by the major Democratic Unionist Party (DUP), were voted down by the nationalist Sinn Fein and SDLP parties via a mechanism where they can essentially veto legislation.The DUP leads the power-sharing government with Sinn Fein under the terms of a 1998 peace deal that ended three decades of sectarian violence in Northern Ireland.The devolution of corporation tax setting powers to Northern Ireland to allow it to compete with the lower rate across the border in Irish Republic is also contingent on the reforms being implemented.The administration is expected to be able to survive until the end of July, but at that point either Britain's Secretary of State to the region would likely to have to step in to enact a budget or London would take back control of welfare.Senior ministers say either option could prompt a walkout by one of the major parties and a collapse or suspension of the administration.The debate came the day after Northern Ireland First Minister Peter Robinson, leader of the DUP, was admitted to hospital. He remains in hospital where his condition was said by DUP deputy leader Nigel Dodds to be improving.