Liberal minority back up to 169 after Elections Canada validates close Ontario race

Elections Canada's validation process has revealed a second closely contested riding's winner has changed after Monday's preliminary result — this time from the Conservatives to the Liberals.

The unofficial results posted on election night showed that Conservative Parm Gill had won the redrawn riding of Milton East-Halton Hills South by 298 votes.

But after double-checking the numbers, Elections Canada now reports that Liberal Kristina Tesser Derksen won by 29 votes.

This latest riding flip brings the Liberals back to 169 seats — three seats shy of a majority — while the Conservatives drop to 143.

The Liberals lost a riding on Thursday after a similar validation process in the Montreal-area riding of Terrebonne revealed that the Bloc Québécois had won.

The validation process — which is different from an official recount — is a way for Elections Canada to verify the unofficial results that are reported on election night. Each local returning officer goes through the results reported by each polling station to weed out any potential errors.

"When you're talking about hundreds of or thousands of polling locations and lots of results coming in, errors can happen. Whether it's something gets misheard on the phone or somebody accidentally types in the wrong number on the keyboard," Matthew McKenna, a spokesperson for Elections Canada, told CBC News before election day.

"The returning officer for each riding goes through the statements of the vote from every poll and makes sure that that's checked against the records so that we can adjust for any little errors or mistakes."

Even after the validation process, both Milton East-Halton Hills South and Terrebonne's final tally are so close that it will trigger an official recount. Such a recount is overseen by a judge and is automatically triggered if a candidate wins by less than 0.1 per cent of the overall vote.

Official recounts have flipped ridings in the past. In 2021, the Bloc candidate was declared the winner of the then-named riding of Châteauguay-Lacolle. But an official recount two weeks later gave the victory to the Liberals.

An official recount will also be triggered in the N.L. riding of Terra Nova-The Peninsulas, where the Liberal candidate edged out the Conservative by 12 votes.