China slammed what it called "groundless slander and defamation" by Canada on Friday, after Ottawa summoned Beijing's ambassador over accusations a Chinese diplomat sought to intimidate a Canadian lawmaker and his family.

"China is strongly dissatisfied with Canada's groundless slander and defamation of the normal performance of duties by the Chinese embassy and consulates in Canada and firmly opposes it," foreign ministry spokeswoman Mao Ning said.

Beijing had "lodged a strong protest" against the move with Canada's ambassador to China, she said.

Parliamentarian Michael Chong has led an outcry in Canada following a damning report this week by the Globe and Mail newspaper that said Ottawa had turned a blind eye to Beijing's interference in Canadian affairs.

The newspaper, citing classified documents and an anonymous security source, said China's intelligence agency had planned to target Chong and his relatives in Hong Kong with sanctions for having voted in February 2021 for a motion condemning Beijing's conduct in Xinjiang province as genocide.

A diplomatic official at China's consulate in Toronto was reported to be involved in the intrigue, leading Ottawa to say it was "assessing different options including the expulsion of diplomats".

Beijing firmly reiterated its denial of any wrongdoing on Friday, insisting the scandal had been "hyped up by some Canadian politicians and media".

Mao said the claims were "completely nonsense and a political farce based on ideological prejudice".

Citing previous disagreements between the two countries that had "seriously damaged China's interests", she also said "it is entirely legitimate and necessary for China to respond forcefully".

Canadian Prime Minister Justin Trudeau has faced growing pressure to take a hard line with Beijing following revelations that it sought to sway Canada's 2019 and 2021 elections.

The accusations, which Beijing has denied, have become the focus of parliamentary committee hearings and investigations by Canada's elections agency.