Open this photo in gallery In a letter on Friday, Conservative Leader Andrew Scheer pressed Prime Minister Justin Trudeau to take a harder line with Canada’s second-biggest trading partner at a time when the countries are locked in a diplomatic dispute that has dragged on for more than seven months. Sean Kilpatrick/The Canadian Press

Conservative Leader Andrew Scheer is urging Prime Minister Justin Trudeau to step up inspections on all products from China and to consider slapping tariffs on imports from the Asian country.

In a letter on Friday, Mr. Scheer pressed Mr. Trudeau to take a harder line with Canada’s second-biggest trading partner at a time when the countries are locked in a diplomatic dispute that has dragged on for more than seven months.

Since the start of the conflict, China has detained two Canadians on espionage charges and has taken trade-related actions against goods from Canada that carry economic consequences.

Story continues below advertisement

“There is no other way to put this: Canada is being bullied by the Chinese government and you have done nothing to stand up for Canada in response,” Mr. Scheer wrote to Mr. Trudeau in the letter, which his office released publicly.

The Canadian Food Inspection Agency, however, has no intention of increasing inspections on Chinese imports, a spokeswoman for Agriculture Minister Marie-Claude Bibeau said later on Friday.

China detained two Canadians in December just days after Canada arrested Chinese high-tech executive Meng Wanzhou in Vancouver on a U.S. extradition warrant.

Angered by Ms. Meng’s arrest, China has increased inspections that have led to the suspension or obstruction of key Canadian agricultural imports, including pork and canola.

Last week, China announced an additional suspension of all imports of Canadian meat products because of claimed concerns over fraudulent inspection reports.

Canada is collaborating with China in a continuing investigation, said Katie Hawkins, Ms. Bibeau’s spokeswoman.

Mr. Scheer wants Mr. Trudeau to respond by intensifying Canadian inspections on all imports from China and to start exploring possible retaliatory levies on Chinese products that will have the greatest possible impact while “minimizing harm” to consumers in Canada.

Story continues below advertisement

He added that Canada imported more than $75-billion in goods from China last year.

“In short, we have leverage in this dispute, but only if we choose to wield it,” Mr. Scheer wrote.

Mr. Trudeau, who has called the detention of the Canadians arbitrary, has tried to secure their release by encouraging Canada’s allies to tell Beijing it needs to follow the rule of law and other international standards.

The Prime Minister and Kelly Craft, the U.S. ambassador to Canada, have said U.S. President Donald Trump raised the plight of Michael Kovrig and Michael Spavor with Chinese President Xi Jinping during the recent Group of 20 summit.

Mr. Kovrig, a Canadian diplomat on leave, and Mr. Spavor, an entrepreneur, were both arrested on allegations of undermining China’s national security.

Mr. Scheer also reiterated his calls for Mr. Trudeau to launch a complaint against China with the World Trade Organization and to cut Canadian funding to Beijing’s Asian Infrastructure Investment Bank, to which the Liberal government has committed $256-million over five years.

Story continues below advertisement

Your time is valuable. Have the Top Business Headlines newsletter conveniently delivered to your inbox in the morning or evening. Sign up today.