A book that argues that Canadian democracy is threatened by the growing power of the Prime Minister’s Office has won the $50,000 Donner Prize as Canada's best book on public policy.

Democratizing the Constitution: Reforming Responsible Government was written by Peter Aucoin, Mark D. Jarvis and Lori Turnbull. (Emond Montgomery Publications)

Democratizing the Constitution: Reforming Responsible Government was written by the late Peter Aucoin, who was a professor emeritus of political science at Dalhousie University in Halifax, Lori Turnbull, an associate professor at Dalhousie and Mark D. Jarvis, a doctoral candidate at University of Victoria.

The award was announced Tuesday evening in Toronto by Allan Gotlieb, chair of the Donner Foundation, which funds the award for public policy writing.

Looking at events in recent history, the book makes the case that the constitution no longer provides effective constraints on power in the PMO. Restoring power to the people’s elected representatives in Parliament is vital, they say, arguing the time-honoured system of responsible government is failing Canadians.

The Donner jury called it "an important and timely book – one that calls into question the legitimacy of our most fundamental institutions of democracy."

A five-member jury comprising A. Anne McLellan, Wendy Dobson, Kevin G. Lynch, Marcel Boyer and Denis Stairs chose the winner.

The other three finalists, who each receive $7,500, are: