Prof Monica McWilliams has been appointed chief commissioner on the Human Rights Commission.
Prof McWilliams, a founder member of the cross-community Women's Coalition, will succeed Professor Brice Dickson at the organisation.
The former Assembly member for south Belfast said she wanted to work with unionists and nationalist politicians and vowed to make a Bill of Rights for Northern Ireland her top priority.
“I have had a long-standing commitment to human rights in Northern Ireland and am looking forward to taking a Bill of Rights forward," Prof McWilliams said. “The main job of work here is going to be completing that work on the Bill of Rights."
But her appointment was condemned by the deputy Democratic Unionist leader Peter Robinson in the House of Commons today.
Mr Robinson protested: “Was the business of the House so tight today that the Secretary of State for Northern Ireland could not have come to the dispatch box to make the announcement about the appointment of the Human Rights Commission in Northern Ireland which he has done by other means.
“Particularly as he has appointed a bigoted, anti-unionist, political reject as the chairperson of that commission, someone who will be incapable of getting the support and confidence of the unionist community,” he said.
Commons Leader Geoff Hoon said Northern Ireland Secretary Peter Hain had set out the details in a written ministerial statement.