The story so far:

On May 8, the Canadian government declared Chinese diplomat Zhao Wei “persona non grata,” for allegedly targeting a Canadian lawmaker critical of China’s human rights record. Hours later, China announced a “reciprocal countermeasure” by asking Jennnifer Lynn Lalonde, a top diplomat in the Canadian consulate in Shanghai, to leave the country by May 13. Tensions soared with China saying it holds the “right to take further actions in response”, while Prime Minister Justin Trudeau put out a strongly worded statement, reiterating that Canada will not be intimidated.

At the centre of the latest spat is a report from the Canadian Security Intelligence Service (CSIS). Earlier this month, The Globe and Mail added, to a series of media reports about growing Chinese interference in Canada, a report on an intel document from 2021 which detailed potential threats to opposition lawmaker Michael Chong and his family in Hong Kong over the latter’s criticism of Beijing. Citing an anonymous national security official as its source, the newspaper reported that Chinese consul Zhao Wei was involved in gathering information about Mr. Chong and his family in Hong Kong to target him over his anti-Chinese sentiments and for further sanctions — to “make an example” of him and “deter others from taking an anti-PRC position.”

In 2021, Mr. Chong led legislative efforts in Canada’s House of Commons to declare China’s treatment of Uyghurs and other minorities in Xinjiang as “genocide”. In response, Beijing barred his entry into China.

After details of the CSIS report were revealed, the Canadian government was heavily criticised for its inaction against China. While Mr. Chong said that he was disappointed to find out about the risk to his family’s life from a newspaper, Mr. Trudeau claimed he was not made aware of the intel by the spy agency. Internal deliberations followed about the future course of action, seemingly to prepare for any economic repercussions since China is Canada’s second-biggest trade partner.

On May 8, Canada declared diplomat Zhao Wei “persona non grata” (Latin for an unwelcome person). In a statement, Foreign Affairs Minister Mélanie Joly said that Canada would “not tolerate any form of foreign interference in our internal affairs.” The Minister added that, “diplomats in Canada have been warned that if they engage in this type of behaviour, they will be sent home.”

China responded strongly, warning of retaliatory measures. In a statement, the Chinese Embassy in Ottawa said Zhao’s expulsion was “based on rumours of the so-called ‘China interference’ hyped up by some politicians and the media.” Terming the move a violation of international law which had sabotaged China-Canada relations, the Embassy maintained that China never interferes in other countries’ internal affairs.

Later, Chinese Foreign Ministry spokesperson Wang Wenbin urged Canada to stop “unreasonable provocations”. “If Canada does not listen to the advice and acts recklessly, China will fight back resolutely and forcefully, and the Canadian side must bear all the consequences arising from this,” Mr. Wang said. Hours later, China issued an order asking Ms. Lalonde to leave the country by May 13.

Diplomatic ties between China and Canada have been unsteady for the past few years, especially after Canadian police arrested Huawei Technologies executive Meng Wanzhou on charges of fraud in 2018. A few days after her arrest, China detained two Canadians on spying charges — a move then called “hostage diplomacy”. After years of a stand-off, all three were freed by their respective nations in 2021 after a deal was reached to release Ms. Meng.

During that period, China suspended imports of canola from Canada, alleging pests in the shipment. The ban was, however, lifted last year amid a global shortage of food in the wake of the Russia-Ukraine war. Since then, the rift has widened.

Canada alleged that the Chinese government attempted to interfere in the 2019 and 2021 federal elections — a charge Beijing vehemently denies. The two countries are also engaged in a technology battle. While Canada has limited the presence of Chinese firms in its communications infrastructure, Beijing believes the restrictions were imposed without any solid evidence.

The tension between the leadership was also visible at the G-20 summit in Indonesia last year, when Chinese President Xi Jinping and the Canadian PM exchanged barbs over leaked details of their meeting about Chinese interference in domestic affairs.