Jim Flaherty — Prime Minister Stephen Harper's only finance minister until he stepped down after delivering the 2014 federal budget — his ninth — saying he wished to return to private life in Whitby, Ont. Flaherty died suddenly of a heart attack in April 2014, just weeks after leaving cabinet, depriving the Conservatives of their senior political representative from Ontario.
John Baird — The Harper cabinet jack-of-all-trades and former Ontario provincial cabinet minister caught even Harper off guard when he announced in February he was leaving his post as minister of foreign affairs, saying he was deeply affected by the passing of his old friend Flaherty and wanted to explore life outside politics. Baird gave up his Ottawa seat shortly after.
Peter MacKay — The co-founder, with Harper, of the modern Conservative party cited his young and growing family when he announced late last month that he would not seek re-election in his rural Nova Scotia riding but would remain on as justice minister until the election call.
Shelly Glover — The bilingual former Winnipeg cop announced in April that it was "time to return to my previous life" after being first elected in 2008, leaving behind her role as heritage minister and official languages minister.
Christian Paradis — Harper's international development minister announced in April he'd consulted with his family and decided it was "time to pass the torch" in his Quebec riding, which includes the town of Lac Megantic, devastated by the 2013 oil train derailment and fire.
James Moore — First elected in 2000 at age 24, the Conservative industry minister announced Friday he would not seek re-election in his lower mainland B.C. riding in order to spend more time with an ailing young son.
Gordon O'Connor — The retired brigadier-general, 75, served as revenue minister and defence minister after being elected in his Ottawa-area riding in 2008.
Diane Ablonczy — First elected to parliament as a Reform party MP in 1993, Ablonczy served as a minister of state in various portfolios, most recently for foreign affairs. She served notice back in 2013 that this would be her last term in her Calgary riding.
James Rajotte — An Edmonton MP since 2000, Rajotte most recently chaired the Commons finance committee and won respect across partisan lines for his intelligence and even demeanour. He announced he wouldn't seek re-election just this month without providing a specific reason.
Joe Preston — The MP for a southwestern Ontario riding around London, Preston was another garrulous and popular Conservative MP who chaired the Commons' often fractious procedure and house affairs committee.
Patrick Brown — A young, low-profile backbencher in the Conservative ranks, Brown vaulted into the spotlight last September when he launched an ultimately successful campaign to become leader of the Ontario Progressive Conservative party, which meant he formally gave up his Barrie, Ont., federal seat in May.