Books on Canadian politicians and the environment highlight this year's Shaughnessy Cohen Prize for Political Writing.

The short list for the $25,000 prize includes Stephen Harper (Signal/McClelland & Stewart) by John Ibbitson, which was a finalist for the British Columbia National Award for Canadian Non-Fiction.

Also on the list is Greg Donaghy for Grit: The Life and Politics of Paul Martin Sr. (UBC Press) and Norman Hillmer for O.D. Skelton: A Portrait of Canadian Ambition (University of Toronto Press).

Sheila Watt-Cloutier made the cut for The Right to Be Cold: One Woman's Story of Protecting Her Culture, the Arctic, and the Whole Planet (Allen Lane), which was also a finalist for the B.C. non-fiction prize.

And Andrew Nikiforuk is a finalist for Slick Water: Fracking and One Insider's Stand Against the World's Most Powerful Industry (Greystone Books).

The winner will be announced in Ottawa on April 20 at the Politics and the Pen Gala.

This year's jury comprises Canadian military historian Tim Cook, author and Globe and Mail journalist Robyn Doolittle, and McGill University professor and political commentator Antonia Maioni.

Now into its 16th year, the Shaughnessy Cohen Prize is sponsored by Aimia and supported by the Politics and the Pen Gala.