China expelled Canada's consul in Shanghai this week, in retaliation for Ottawa's expulsion of a Chinese diplomat accused of attempting to intimidate a lawmaker.

After years of strained relations, the expulsions have rekindled tensions between the two countries.

They come after a Canadian outcry over allegations that Chinese intelligence planned to sanction MP Michael Chong and his relatives in Hong Kong for sponsoring a motion condemning Beijing's actions in the Xinjiang region as genocide.

In response, Canadian Foreign Minister Melanie Joly stated that Chinese diplomat Zhao Wei, who is based in Toronto and allegedly played a role in the scheme, would be required to leave the country.

She stated that Canada would "not tolerate any form of foreign interference in our domestic affairs."

The Chinese foreign ministry condemned Zhao's expulsion decision on Tuesday, saying it had ordered Canadian consul Jennifer Lynn Lalonde to leave the country by May 13.

"As a retaliatory measure in response to Canada's shady move, China has decided to declare Jennifer Lynn Lalonde, consul of the Consulate General of Canada in Shanghai, persona non grata," the ministry said in a statement.

Wang Wenbin, a spokesman for China's foreign ministry, also urged Canada to refrain from "unreasonable provocations."

"If the Canadian side ignores this advice and acts recklessly, (China) will take resolute and forceful retaliatory measures, and the Canadian side will bear all consequences," Wang said at a regular press briefing.

According to AFP journalists, a single police car was parked outside the Shanghai office building where the consulate is located.

Inside, appointments appeared to be proceeding normally, and receptionists claimed to be unaware of the events of Tuesday.

AFP's requests for comment were not responded to by either Canada's foreign ministry or its embassy in Beijing.

"We remain steadfast in our conviction that defending our democracy is of the utmost importance," Joly said on Monday, adding that foreign diplomats in Canada have been "warned that if they engage in this type of behavior, they will be sent home."

Following recent revelations that China attempted to sway Canada's 2019 and 2021 elections in his party's favor, Prime Minister Justin Trudeau has faced increasing pressure to take a hard line on China.

Relations between Beijing and Ottawa have been strained since Canada arrested a top Huawei executive in 2018 and, in apparent retaliation, detained two Canadian nationals in China.

All three have been released, but Beijing has continued to criticize Ottawa for supporting Washington's China policy, while Canadian officials have frequently accused China of meddling.

Following the summons of China's ambassador last week in connection with the latest allegations of interference, Beijing condemned Canada's "groundless slander and defamation" on Friday.

The Chinese foreign ministry insisted that the scandal had been "hyped up" by Canadian politicians and the media.

Chong told reporters in Ottawa on Monday, "It shouldn't have taken the targeting of a member of Parliament to make this (expulsion) decision."

"We've known for years that the PRC is targeting Canadians and their families through its accredited diplomats here in Canada," he said, using the acronym for the People's Republic of China.

He claims that Canada has turned into a "playground for foreign interference," including harassment of diaspora communities.