Conservative Leader Andrew Scheer accused former Canadian ambassador to China John McCallum of inviting foreign interference in the upcoming federal election after McCallum said he warned Chinese officials to lay off future trade barriers because they could help the Conservatives win.

McCallum told the South China Morning Post that he advised his former contacts in China’s ministry of foreign affairs that any more “punishments” on Canadian exports could help the Tories win October’s election -- a win he said would not be in China’s best interests.

“Anything that is more negative against Canada will help the Conservatives, [who] are much less friendly to China than the Liberals,” McCallum told the newspaper on Monday.

Hours after the article was published, Scheer issued a statement slamming McCallum and calling his comments an “invitation of foreign interference in the Canadian election.”

“I forcefully and unequivocally condemn recent comments by high-profile Liberals encouraging the Chinese government to help re-elect the government this October,” Scheer said, describing the comments as “reprehensible.”

The Prime Minister’s Office ordered McCallum to hand in his resignation in January after he chimed in on the sensitive, high-stakes extradition case of Huawei executive Meng Wanzhou. McCallum told a Vancouver newspaper that it would be “great for Canada” if the U.S. dropped the extradition request.

Since Meng’s arrest in Vancouver last December, China has slapped several trade barriers on Canadian products including canola seeds and meat. Canadians Michael Kovrig and Michael Spavor were later detained in China, where they have been held for more than seven months on espionage charges that Canadian officials consider an illegitimate act of retaliation.

Scheer said McCallum’s latest comments demonstrate Trudeau’s “poor judgement” in picking him for the high-profile international post.

Before moving to Beijing, McCallum served as Trudeau’s minister of immigration, refugees and citizenship until 2017.