Harper says Ottawa can no longer initiate any constitutional amendment related to Senate reform because of the high court's decision.
He told a news conference in Montreal today that if the provinces are serious about such reform, then so is he.
The Supreme Court ruled last Friday that Ottawa needs the approval of at least seven provinces containing 50 per cent of Canada's population in order to impose term limits on senators or create a consultative election process to choose senators.
It also said the consent of all the provinces and the Senate is required to abolish the upper chamber.
Harper was in Montreal to make an announcement aimed at fighting autism and Alzheimer's disease.