1990 York North federal by-election

A by-election was held in the federal riding of York North in Ontario on December 10, 1990, after the 1988 election of Liberal member of Parliament (MP) Maurizio Bevilacqua was voided by the Supreme Court of Ontario.

In the 1988 federal election, Progressive Conservative candidate Micheal O'Brien was declared the winner for York North following a judicial recount and served 55 days as the MP for the riding. However, a second judicial recount reversed the result, and Bevilacqua was declared elected by a margin of 77 votes, marking the first time in Canadian history that two MPs had been sworn in for the same riding as the result of a single election. In May 1990, the court annulled the result over voting irregularities, the first such ruling since 1957.

Bevilacqua won the ensuing by-election by more than 7,000 votes over the second-place NDP candidate, while the Progressive Conservatives fell to third place. The by-election was held on the same day as another federal by-election in Beauséjour in New Brunswick.

In the 1988 election, held November 21, 1988, Progressive Conservative candidate Michael O'Brien was initially declared the winner for the riding of York North by a margin of 66 votes.^[1] Three days later, however, Liberal candidate Maurizio Bevilacqua was declared the winner when the official tabulation showed he had won by 66 votes.^[2]

O'Brien requested a judicial recount and, on November 30, an Ontario judge ruled that 3,547 votes could not be counted because their envelopes had been signed by only one poll clerk rather than the required two. O'Brien was then declared the winner by a margin of 99 votes and was sworn in as the member of Parliament (MP) for York North.^[1]

Bevilacqua appealed the decision to the Ontario Supreme Court and, on December 15, the court overturned the lower court's ruling and ordered a second judicial recount. The recount was completed on January 11.^[1] The final tally showed Bevilacqua had defeated O'Brien 37,513 votes to 37,436 votes, a 77-vote margin.^[3] Bevilacqua was sworn in later that month after O'Brien had served 55 days as MP,^[4] marking the first time in Canada that an election had led to the swearing-in of two MPs for the same riding.^[5]

O’Brien then filed a petition under the Controverted Elections Act, arguing that numerous violations of the Canada Elections Act had compromised the vote.^[6] The Ontario Supreme Court heard evidence of mistakes affecting 121 ballots, enough to potentially alter the 77-vote margin. Most of the cases involved voters who had been mistakenly left off official voters' lists, but who were still allowed to vote. In several cases, electors were vouched for by individuals who not on the voters' list themselves, contrary to the requirements of the Canada Elections Act.^[2][7][8]

On May 29, 1990, the Ontario Supreme Court declared the election results void. This ruling marked the first time a court had nullified an election result since Yukon was overturned following the 1957 federal election.^[7]

Under the Controverted Elections Act, Bevilacqua had eight days to appeal the ruling to the Supreme Court of Canada.^[7] However, he announced on June 5 that he would not appeal the ruling, noting the litigation had already cost him between $50,000 and $70,000.^[9] The York North riding was declared vacant by John Fraser, Speaker of the House of Commons, on June 7.^[10]

A by-election was held on December 10, 1990, the same day as another by-election in Beauséjour in New Brunswick.^[11] Bevilacqua won the seat by more than 7,000 votes over the second-place NDP. O'Brien, who again represented the Progressive Conservatives, was pushed into third place.^[5]

• 1997 Winchester by-election, a by-election in England held under identical circumstances