UUP leader Jon Burrows called Sinn Féin “morally bankrupt” and said the party had “a recurring problem with accountability”.
“We have a party that simply will not sign up to the normal rules of democracy,” he told the assembly.
Addressing those on the Sinn Féin benches, Burrows said they should be “ashamed of their conduct”.
Earlier, he told BBC Radio Ulster’s Nolan Show he would not withdraw Health Minister Robbie Butler from the executive, “because to do so would affect the people of Northern Ireland in all the work he is doing”.
Burrows said he was instead calling for changes to Stormont’s rules, and said there should be “proper accountability mechanisms” to hold ministers who breach the pledge of office to account.
Alliance Party deputy leader Eóin Tennyson branded the no-confidence motions a “political stunt” designed to collapse Stormont.
Tennyson described the debate as “depressing, dispiriting and almost unbelievable”, warning that power-sharing institutions were “once again being placed in jeopardy”.
However, he also said any elected representatives found to have acted unlawfully in recent weeks “should face the consequences of that conduct”.
Social Democratic and Labour Party (SDLP) assembly member Matthew O’Toole, leader of Stormont’s official opposition, welcomed the NI Secretary’s decision to ban the Drumcree parade, a dispute which he said had “opened up deep wounds that didn’t need to be reopened”.
O’Toole said he was not “diminishing or trivialising the rule of law” and his party would “cooperate” with investigations.
“Because we do accept the rule of law and the need for the PSNI and the courts to do their job,” he added.
“But we were also founded, the SDLP, in the tradition of peaceful protest.
“That’s in our DNA and that right is sacrosanct, and sometimes such action is unavoidable.”
