In 1984, Brian Mulroney led the Progressive Conservatives to victory nationally, having committed during the campaign to try to find a way to accommodate Quebec's objections to the constitution. Lévesque pledged to take the risk of trying to work towards a deal with Mulroney. This led to a split in the PQ and subsequently Lévesque's resignation from politics in 1985. After the PQ defeat by the Liberals of Robert Bourassa, the Mulroney government began negotiations with Quebec to find a deal that would be acceptable to all provinces. The 1987 Meech Lake Accord and the 1992 Charlottetown Accord, despite receiving unanimous consent among the provincial premiers, each failed in dramatic public fashion, reviving the sovereignty movement.