TORONTO -- Finance Minister Dwight Duncan says he's leaving politics to give Ontario's premier-designate a "free hand" to renew the Liberal government.

Duncan has announced plans to quit as the MPP for Windsor-Tecumseh, effective Feb. 14.

He says he was a key figure in Premier Dalton McGuinty's cabinet, and it's very important that incoming premier Kathleen Wynne has the opportunity to put her own stamp on the Liberal front bench.

Duncan told reporters at Queen's Park that he's always believed governments have a natural lifespan of about eight years, unless they renew.

He adds there are many talented Liberal backbenchers who have not yet had the opportunity to serve in cabinet.

Duncan lost when he ran against McGuinty for the Liberal leadership in 1996 but became his finance minister after Greg Sorbara bowed out.

McGuinty released a statement this morning thanking Duncan for his "steady hand" and many years of service.

He praised Duncan for reforming Ontario's tax system, helping harmonize sales taxes with the federal government and for working to protect the auto industry during the recession.

Duncan's resignation will clear the way for a byelection in Windsor-Tecumseh. He has represented Windsor-area ridings since 1995.