Canada's national police force says nothing tops muskrat fur for keeping officers' heads warm in extreme cold, and it has issued a tender for 4,470 of its traditional blue winter hats with ear flaps, lined and trimmed with muskrat fur.

"The fur must be Eastern Canada or New York state spring muskrat No. 1 quality, fully furred. Only extra-large skins with the belly trimmed off must be used," reads the request for proposals, published online.

Each hat is made of two to three pelts, which means it will take roughly 12,000 muskrats to fill the order.

That's not going over well with some wildlife advocates.

"We knew that they would be keeping some of the hats for some of their cold weather extremes. They didn't want to do away with them altogether, but it is sad that they're putting out a tender for such a large amount," said Adrian Nelson of Fur Bearers, a wildlife advocacy group in Vancouver.

Nelson told CBC News that for years now, Fur Bearers has been lobbying the RCMP to ditch the muskrat hats, and the group had been making progress — until 2014.

That's when the Mounties introduced wool winter tuques and the fur really began to fly.

The Conservative government at the time stepped in and ordered the police force to keep the traditional winter hats.

Fur vs. wool tuques

"I think that as more and more officers demand the tuques and we see more of them making that cruelty-free choice, I think we're going to see less of these hats needed, and hopefully we can get them to phase this out," said Nelson. "What's more Canadian than a tuque?"

This time around, the government is staying out of the controversy. A spokesperson for Ralph Goodale, the minister who oversees the RCMP, said that what Mounties wear is an operational decision for the police force.

Each RCMP winter hat requires the pelts of two to three muskrats. (Shawn Gust/The Coeur d'Alene Press/Associated Press)

Trappers, though, welcome the business.

"It's nice to see that recognition of Canadian heritage. The fur trade is part of Canada's history, of course, and still makes a lot of sense today because it is a natural, biodegradable, renewable resource," said Alan Herscovici, speaking for the Fur Council of Canada and website Truth About Fur.

He said that in 2016, Canada's rural trappers made $1.7 million from harvesting around 315,000 muskrats.

"Trappers in Canada have to take training courses to learn how to use the new humane trapping methods before they get their trapping licences, and it is extremely well-regulated by the provincial and territorial wildlife departments," Herscovici said.

In an email to CBC News, the RCMP said it will only buy from approved suppliers who use legal and humane methods for harvesting fur. The national police force has conducted in-house tests on fake fur, but said it just didn't perform as well in cold, wet conditions.

"The uniform and equipment program was unable to identify an alternative material that matched or exceeded the performance of muskrat fur in extreme cold weather conditions," wrote RCMP spokesperson Cpl. Annie Delisle.

That said, the choice of wool or fur is up to each individual Mountie.