UUP leader Mike Nesbitt meets Prime Minister David Cameron
UUP leader Mike Nesbitt has told the prime minister the government must not collapse the Northern Ireland Executive over welfare reform difficulties.
Mr Nesbitt made the comments during a meeting with David Cameron in the House of Commons.
It was the first time in over a decade that an Ulster Unionist leader has met the prime minster at the beginning of a new parliament.
Mr Nesbitt said he urged him "not to step in and collapse the institutions".
The UUP leader said the Northern Ireland parties had to "sort this out for ourselves".
He claimed that "Sinn Féin have flip-flopped over welfare reform", adding that if the party "really care about the vulnerable they will stop pouring £2m a week down the drain".
Last Friday, First Minister Peter Robinson said he believed the UK government would rather take direct charge of welfare powers than witness the collapse of the Stormont Executive.
The DUP leader also said his party would not back a budget that would contain a £500m black hole in the absence of a welfare deal.
Mr Robinson also said that Stormont could not implement a further wave of welfare reform, which is another reason why London may have to take control.
During his meeting on Monday with Mr Cameron, Mr Nesbitt also raised mental health issues and economic matters.
A spokesman for Downing Street described the meeting as routine and private.