Joe Tay, an actor and journalist running in Monday’s federal election in Canada, has not ventured outside to knock on constituents’ doors. He has not buttonholed voters at the local strip mall. Nor has he been seen schmoozing at public gatherings.

Fearing for his safety, Mr. Tay — a critic of the Chinese government, which has placed a bounty on Mr. Tay and offered $130,000 for information leading to his arrest, and who is running in a key electoral district in Toronto — has waged perhaps the quietest campaign of any candidate competing in the election.

And days before the vote, Mr. Tay’s ability to campaign shrank even further as Canadian government officials revealed that he had been the subject of coordinated online attacks on Chinese-language sites linked to the Chinese government. For the past four years, Mr. Tay has denounced China’s tightening grip on Hong Kong and the disappearance there of democratic freedoms.

The attacks sought to discredit Mr. Tay, a Conservative, portraying him as a criminal, and to suppress information about his candidacy, Canadian officials said at a news conference this past week.

“There is a narrative being amplified by the P.R.C. government,” Vanessa Lloyd, the head of Canada’s intelligence agency, said, referring to the People’s Republic of China.

The attacks on Mr. Tay have sought to influence the outcome of the race in Don Valley North, a district with a large Chinese diaspora in Toronto, in what is the most vote-rich region in Canada.