A statement by Elections Canada on Sunday afternoon said it issued three writs for a trio of Oct. 19 byelections to be held in the ridings of Ottawa West-Nepean, Peterborough and Sudbury.
Former foreign affairs minister John Baird left Ottawa West-Nepean vacant with his resignation from Parliament in March.
Peterborough is vacant because former Conservative MP Dean Del Mastro was found guilty last fall of violating the Canada Elections Act.
Former New Democrat MP Glenn Thibeault resigned his Sudbury seat in January to join the Ontario Liberals.
Under electoral law, a byelection must be called within 180 days of the Chief Electoral Officer receiving notice of a vacant seat in the Commons.
In the case of Del Mastro's riding, that 180-day deadline was coming up on Wednesday. Del Mastro's seat was formally vacated on Nov. 7.
The deadlines for byelection calls in Baird's and Thibeault's ridings are in September and July respectively.
A spokesperson for Elections Canada says the byelections would be superceded if a general election is held before Oct. 19.
Baird stunned observers in February when he announced he was quitting federal politics after almost four years as Prime Minister Stephen Harper's top diplomat and nearly a decade as one of his most trusted and versatile ministers.
Since then, Baird has landed three lucrative private sector jobs: he's now a member of Barrick Gold's international advisory board, a director of Canadian Pacific Railway, and he's become an adviser to a Hong Kong billionaire.
Baird is one of several Conservative cabinet ministers to step down ahead of the expected Oct. 19 federal ballot. International Development Minister Christian Paradis and Canadian Heritage and Official Languages Minister Shelly Glover recently announced they won't be seeking re-election.
Del Mastro's political career came to a more ignominious end, after he was found guilty last fall of exceeding spending limits, failing to report a personal contribution of $21,000 to his own campaign and knowingly submitting a falsified document during the 2008 federal election.
The disgraced ex-MP, who had previously helped defend the Conservatives against electoral fraud allegations, choked back tears in an Ontario courtroom last week before a judge adjourned the proceedings to decide whether or not to send him to jail.
Controversy also surrounds Thibeault's resignation and defection to the Ontario Liberals.
The Ontario Provincial Police questioned Premier Kathleen Wynne last week about allegations her party offered a former candidate a job or appointment to step aside to make room for Thibeault.
Thibeault won the provincial riding of Sudbury in a separate byelection in February, less than a month after leaving federal politics.
The leaders of the Ontario Progressive Conservatives and New Democrats have said it is "unseemly" and "appalling" for a sitting premier to be questioned by police.
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