OTTAWA—Canadian Prime Minister Justin Trudeau fell brief on his gambit of capturing a parliamentary bulk in national elections and now faces demands from a remaining-wing rival social gathering to shore up healthcare spending and elevate taxes on the wealthy.

The preliminary outcomes from Monday’s election suggest Canadians have reservations about the primary minister that consist of a report of ethical breaches and his conclusion to keep a snap vote through the Covid-19 pandemic. But the outcomes also suggest voters weren’t enamored with Mr. Trudeau’s rivals, as opposition functions designed no discernible gains relative to the 2019 election.