UUP MP Danny Kinahan wants Westminster to review changes to the Belfast Agreement that were made to accommodate the DUP and Sinn Féin agreeing to share power in 2007.
He said Westminster must restore integrity of Stormont institutions and that provisions of the St Andrews Act should be reversed.
Expressing regret at the current scandal enveloping Stormont, Mr Kinahan said: “My Party fought hard to end the wholesale violence on our streets and establish a truly inclusive set of political institutions. It is deeply embarrassing to see those institutions brought into such disrepute by those currently at the heart of the Stormont Executive.
“I believe Westminster needs to take action to start the process of restoring faith in the integrity of the institutions.
“That includes reversing some of the provisions of the St Andrews Act of 2007, which changed fundamental safeguards in the Good Friday Agreement that had been endorsed by the public in a Referendum.
“In 1998, we ensured the First Minister and deputy First Minister were elected on a single, joint ticket, reflecting the joint nature of the roles. The DUP had that changed by Westminster to save Ian Paisley’s blushes as otherwise he would have had to support Martin McGuinness as deputy first minister.
“That is the root cause of the problem, the inability of the two parties to work together. It over-rides the will of the people, ensures Assembly elections are fought not on the issues, but on a raw sectarian headcount, and holds us back from our vision of a post-sectarian society.
“I shall continue to raise this problem, and the misuse of the Petition of Concern at every opportunity, including at the Northern Ireland Affairs Committee.
“The people of Northern Ireland deserve leadership that recognises the concept of the greater good. It is sadly incumbent on Westminster to take steps to help make that happen.”