Concern has been expressed following the resignation of the Northern Ireland Secretary that the region is now being run by the civil service.
Ulster Unionist leader Doug Beattie described the situation as “as bad as it gets”.
He said the resignation of Brandon Lewis left Northern Ireland without a Secretary of State, while the Stormont Assembly remains collapsed.
Mr Lewis announced his resignation early on Thursday, tweeting a copy of his resignation letter in which he told the British prime minister that he had “given you, and those around you, the benefit of the doubt”.
“We are, however, now past the point of no return. I cannot sacrifice my personal integrity to defend things as they stand now. It is clear that our Party, parliamentary colleagues, volunteers and the whole country, deserve better,” he said.
Mr Beattie told the BBC: “We’re spectators here looking at what’s going as this omnishambles presents itself to us.
“We have no proper functioning government in the UK, we have no Secretary of State, we have no Assembly and we have no Executive and we are being run by the civil service now as it stands, and if Northern Ireland or anywhere else in the UK were to have a major incident, I doubt we could even get the COBR committee to come together to be able to create any form of response.”
Alliance MP Stephen Farry described a “completely crazy situation” and described Boris Johnson as a “narcissistic self-entitled fool”.
“The fact it even got to this point is damning in itself,” he said, and also questioned the DUP’s silence on Mr Johnson.
Meanwhile, prominent victims campaigner Raymond McCord welcomed the resignation of Mr Lewis.
The former Secretary of State attracted the ire of victims’ groups over his proposed legislation to deal with Northern Ireland’s troubled past.
The Northern Ireland Troubles (Legacy and Reconciliation) Bill offers an effective amnesty for Troubles crimes for those who co-operate with an information body.
Mr McCord said: “He (Mr Lewis) has betrayed the victims of the Troubles with the Legacy Bill that gives an amnesty to murderers.
“Brandon Lewis decided to reward the murderers with amnesties for the murders they committed, and punish the victims and their families by ensuring all routes to justice and even civil cases are closed down.
“He insulted all victims by claiming it would help us. He certainly will not be missed by victims.”