Marijuana-loving Montrealers assembled on Mount Royal Sunday to express their mutual appreciation of the forbidden weed.

Participants of the 420 annual international day of celebration and activism partook in an annual event held on April 20th in Montreal and other cities.

This year's local event started Sunday afternoon at noon near the winged monument to Sir Georges Etienne Cartier and was scheduled to finish at 4:20 p.m. with the awarding of prizes for best poster and best pot plant.

Montreal police traditionally tolerate the event and this year their approach remains unchanged. Police media relations agent Jean-Pierre Brabant told CTV Montreal Sunday that a police presence was planned, but only to, “ensure the safety of participants.”

The spot on Mount Royal is known for its longstanding weekend "tam-tam" impromptu bongo jam sessions, so not all of those present Sunday were there exclusively for the 420 celebration.

The annual day of celebrating cannabis culture is ramping up into mainstream political activism as the pot-smoking 420 movement takes on marijuana prohibition with rallies across Canada.

In Ottawa, police advised motorists to steer clear of Parliament Hill in the national capital as a large demonstration is expected for the annual April 20 event, when pot activists traditionally partake at 4:20 in the afternoon.

The 420 moniker dates back to the pot culture of California in the early 1970s, but it became formally attached to April 20 when a group of Vancouver activists held the first day-long rally in 1995.

Anti-prohibition activist Jodie Emery says recent legalization in two U.S. states has opened the eyes of governments and businesses to the financial benefits of a legal trade in marijuana.

And she says that has given the annual 420 rallies -- which have now gone global -- a renewed emphasis on influencing government policy.

As Emery puts it, "we've won over the Man and the establishment."

-With a file from The Canadian Press