A Manitoba dairy farmer has booked a last-minute flight to Washington, D.C., as trade talks between Canada and the U.S. take on a new urgency.

David Wiens, chair of Dairy Farmers of Manitoba, says he’s concerned that Canada’s supply-managed dairy system could be scrapped in order to get a deal with U.S. President Donald Trump. He wants the Trudeau government to protect it.

Supply management refers to the federally regulated system used to limit the supply of dairy that is produced while setting the price farmers receive and keeping out foreign milk through tariffs.

After reaching a preliminary trade deal with Mexico this week, Trump publicly highlighted Canadian tariffs on U.S. dairy products. “We're not going to stand for that,” the president said of the tariffs on Monday.

Without the system, Wiens says the prices Canadian farmers receive for their milk would drop by 50 per cent and some farms might go out of business. “Obviously once the farming is no longer sustainable, then that’s it,” he said.

"For consumers it's important, too,” Wiens added. “They do have a wide range of high quality sustainably-produced dairy products.”

Supply management advocates argue that Canadian milk is of higher quality because – unlike U.S. milk – it’s free of antibiotics and the growth hormone rBST.

Wiens says that the supply management is not a subsidy, while the U.S. does have subsidies. Some consider U.S. insurance and food stamps to be subsidies.

Wiens says the Trudeau government has been strongly supportive of supply management in the past, but it’s still important for farmers to make their presence known as Foreign Affairs Minister Chrystia Freeland continues to negotiate a new deal.

In addition to Trudeau’s Liberals, federal Conservative Leader Andrew Scheer and Quebec Premier Philippe Couillard strongly support supply management. Quebec has the biggest number of dairy farms in Canada at 5,368, followed by Ontario at 3,613.

Some high-profile politicians, however, have sided with Trump. Former Conservative Maxime Bernier opposes supply management on the grounds that it increases prices for Canadian consumers.

Former foreign affairs minister Lloyd Axworthy, meanwhile, says supply management is likely to be on the table at this week’s negotiations whether farmers like it or not, and he thinks that’s a bad thing.

“While it looks like it's a subsidy, it also stabilizes our farming community, also our supply,” Axworthy said. “We have good dairy products,” he added.

With a report from CTV Winnipeg’s Josh Crabb