OTTAWA -- After enduring months of withering fire from Donald Trump's bombastic Twitter feed, Canada's dairy industry waded into the fray on Monday by accusing the U.S. president of wanting to put Canadian farmers out of business.

Yet even as it did so, some in this country were calling for major reforms to the very system of protections for Canada's dairy, egg and chicken farmers that first ignited -- and has continued to sustain -- Trump's anger: supply management.

Trump's most recent salvo came in a series of tweets from Singapore late Sunday, where he again blasted Canada for charging a 270 per cent tariff on U.S. dairy imports, and levelled more personal attacks at Prime Minister Justin Trudeau.

Dairy Farmers of Canada president Pierre Lampron, which represents Canada's roughly 12,000 dairy producers, fired back Monday by blasting Trump's "personal attacks on our prime minister" and defending its supply-managed system.

"Canadian dairy farmers and their families are concerned by the sustained attacks by President Trump with an aim to wiping out dairy farmers here at home," Lampron added.

The comments came as MPs from various parties followed what has become a tradition in Canada: declaring their unwavering support for farmers and the oft-maligned supply management system, which was first established in the 1970s.

Agriculture Minister Lawrence MacAulay was grilled by the NDP during question period after Trudeau indicated on NBC's "Meet the Press" last week that the government was open to relaxing the system as part of a new NAFTA deal.

"Our government strongly supports and is fully committed to maintaining the supply management system," MacAulay replied. "The prime minister has indicated this clearly ΓǪ and our negotiators at the NAFTA table have also indicated this clearly."

Yet some say it is past time to phase out the system, which limits dairy, egg and chicken production in Canada and imposes steep tariffs on foreign imports beyond a certain amount to keep the market from becoming saturated.

For dairy products, which has been the focus of Trump's anger, those tariffs range from nearly 300 per cent for excess imports of butter and cream to 270 per cent for certain dairy powders to 240 per cent for cheese, whole milk and yogurt.

"No one wants to look like they're conceding anything to Trump," said Martha Hall Findlay, a former Liberal MP and leadership candidate who is currently president of the Calgary-based Canada West Foundation and a longtime advocate of ending supply management.

"But this is a huge opportunity. We should actually move beyond supply management. It's good for Canada, it's good for the dairy industry."

Proponents of the system as it stands say it protects Canadian dairy, egg and chicken farmers from damaging price fluctuations in a manner that's comparable to the way other countries support their agricultural sectors with subsidies.

Critics like Hall Findlay say it is a barrier to successful free-trade deals such as NAFTA, and increases the cost of dairy, eggs and chicken for consumers, which has an unfairly disproportionate impact on low-income families.

Yet there is also a tacit acknowledgment of the reality that virtually all federal political leaders face when it comes to supply management: the farmers who benefit are grouped in key ridings, particularly in Ontario and Quebec.

In his forthcoming new book, Conservative MP Maxime Bernier suggests that his opposition to supply management was one of the reasons -- if not the main reason -- that he lost last year's Conservative leadership campaign to Andrew Scheer, who supports it.

The Harper Conservatives planned to ease restrictions on foreign dairy imports in 2015 as part of its plan to sign onto the Trans Pacific Partnership, an 11-country free trade agreement.

But the Harper government was uniquely positioned, said Christopher Sands, director of the Center for Canadian Studies at Johns Hopkins University, in that it had money to compensate farmers, few seats in Quebec and a massive trade deal to sell at the time.

For Trudeau, "there are fewer things he can get in exchange, there isn't money to splash around to get farmers who have a quota to give it up and this is an important issue in Quebec, which provides many seats for the Trudeau government."

Jason Clemens, executive vice-president of the Vancouver-based Fraser Institute, which has long opposed supply management, nevertheless suggested it is potential winner for Canadians -- and any party brave enough to take a stand.

"If we had a federal leader who's willing to stand up and say: 'Yes, I'm willing to lose those seats in Ontario and Quebec because this is a national issue and we need to reduce prices on staple goods for all Canadians, particularly the poor,' I think there would be resounding support for that policy."