Canada has expelled a Chinese diplomat in response to allegations that the diplomat had been involved in efforts to intimidate a Canadian lawmaker who is a vocal critic of the Chinese government’s human rights record.

According to sources familiar with the matter, the expelled diplomat is Cong Peiwu, who served as China’s ambassador to Canada until January of this year. Cong had been accused of coordinating efforts to intimidate Canadian lawmaker Michael Chong, who has been critical of China’s treatment of its Muslim Uighur minority.

The allegations were first reported by Canada’s Globe and Mail newspaper in late April. The report stated that Cong had warned Chong during a virtual meeting in October 2020 that if Canada granted asylum to Hong Kong pro-democracy activists, it could face repercussions from China. Cong also reportedly accused Chong of “supporting separatism” in Taiwan and Hong Kong.

Canada’s Foreign Affairs Minister, Marc Garneau, confirmed on Friday that the government had taken action in response to the allegations. In a statement, Garneau said that the government had summoned Cong and informed him that he was “no longer welcome in Canada.”

The expulsion of a diplomat is a significant diplomatic move, and it is likely to further strain relations between Canada and China, which have been tense in recent years. The two countries have been engaged in a bitter dispute since late 2018, when Canada arrested Huawei executive Meng Wanzhou at the request of the United States.

China responded to Meng’s arrest by detaining two Canadian citizens, Michael Kovrig and Michael Spavor, on espionage charges. The two men have been held in detention in China for more than two years, and Canada has repeatedly called for their release.

The expulsion of Cong is likely to exacerbate tensions between Canada and China, but it also sends a strong message that Canada will not tolerate foreign interference in its political affairs. The move is also likely to be welcomed by human rights activists who have been pushing for Canada to take a tougher stance on China’s treatment of its Uighur minority.