Canadian gun control advocates are calling upon Mountain Equipment Co-op (MEC) this week to discontinue selling every product from every brand owned by the U.S. corporation Vista Outdoor Inc.

Vista, based in Utah, manufactures and markets products for about 50 different outdoor sports and recreation labels – more than half of which produce ammunition and firearms, like the AR-15 rifle used to kill 17 people earlier this month at a high school in Parkland, Florida (among other deadly U.S. shootings.)

Hey @mec, time to take a stand and drop these products. In good faith I can't support your store until you stop supporting a manufacturer of AR-15s.#boycottMEC https://t.co/rpoMoN6YKw — Bruce (@bruce_) February 25, 2018

MEC doesn't sell semi-automatic or assault weapons.

It does, however, stock helmets, goggles, binoculars, camping gear, paddleboards and other outdoor lifestyle products from brands owned by Vista, such as CamelBak, Giro, Bushnell and Bollé.

American cyclist and blogger Aaron Naperstek pointed out the connection on Twitter last week, sparking widespread backlash among consumers who were upset to learn that they'd been buying gear from a company that supports the NRA.

So, the same company that makes my favorite Giro bike helmet -- as it happens, the only helmet that fits on my oddly shaped Cro-Magnon skull -- is really bummed out that assault weapon sales are down since Obama left office. https://t.co/vedyvAVFDW — Aaron Naparstek (@Naparstek) February 21, 2018

Thousands have since pledged online to stop shopping at stores that sell brands owned by Vista - and the corporate boycott is spreading north of the border.

"As members of Mountain Equipment Co-op (MEC), we call on MEC to immediately stop the sale of all Vista Outdoor brands," reads a change.org petition created on Saturday.

dear @mec we are suspending our MEC shopping until you stop carrying products from @VistaOutdoorInc. Hope to see you act on this soon. Our family. https://t.co/KeiYrx8z1T — siobhan o'flynn, phd (@Sioflynn) February 26, 2018

"Vista, through its myriad of other gun and ammunition producing companies, derives about 40% of its yearly profits from the sale of weapons," it continues. "Vista Outdoor is also heavily enmeshed with the gun lobby, with deep financial ties to the National Rifle Association (NRA)."

The petition calls on MEC to "act in accordance with its mission and values" by immediately ceasing to sell brands owned by Vista Outdoor, "a corporation whose profits are derived from the production of assault weapons capable of mass murder."

Hi @mec. I'm also a member and I want you to discontinue selling Camelbak, Giro, and Co-Pilot, which are brands owned by Vista Outdoor, the largest gun manufacturer in the U.S, which makes AR-15s. #GunControl #NRABoycott — Tricia Wood (@pkbwood) February 26, 2018

A similar call to action was posted to Facebook that same day, riling up MEC members on social media and prompting many to address the co-op directly.

"Friends who love spending time in the outdoors, and are @mec members. Please consider asking them not to carry @VistaOutdoorInc products as they also produce and sell AR-15's," wrote one co-op member on Twitter.

"We as Canadians can do our part to help children in the US by divesting from killing machines."

Thank you @mec members who contacted us with your concerns about Vista Outdoors. Senior mgmt will be discussing this first thing on Monday. We'll have an update for you later in the day. — MEC (@mec) February 26, 2018

MEC issued a statement to address the mounting pressure from its members on Sunday evening.

"Thank you @mec members who contacted us with your concerns about Vista Outdoors. Senior mgmt will be discussing this first thing on Monday. We'll have an update for you later in the day."

MEC later posted this update on Monday afternoon.