A Sinn Fein motion questioning whether or not the Welfare Reform Bill was compatible with human rights failed to pass, on 22 October 2012.
The party's West Belfast MLA Fra McCann said he had brought the motion before the house due to his "genuine concern" over the bill.
He said it could have the potential to make thousands of people homeless and his party was opposed to its passage through the Assembly.
The bill, if passed, will bring the changes brought about at Westminster into effect in Northern Ireland.
The UK's coalition government has promised to "make work pay" with plans to ensure people in work are better off than the unemployed.
A universal credit, sanctions for those turning down jobs and a cap on benefits paid to a single family are among the changes outlined.
The motion referred to the Assembly's standing order 34. It allows a motion seeking clarification from the Northern Ireland Human Rights Commission on the bill to be brought at any time after a bill's introduction.
Mr McCann said members of his party had already met with the commission to question if the bill was compliant.
"It was quite obvious the answer was no," he said.
He added that the commission had said it was "difficult, if not impossible to determine human rights compliance".
Social Development Minister Nelson McCausland said he was "surprised" by the motion and said his department had conducted a full analysis of the bill's compatibility with human rights.
He said it had also been approved by the Departmental Solicitors Office.
The motion fell with 40 voting for and 44 against.