A B.C. environmental group's efforts to use the Canadian loonie to spread an environmental warning have hit a bit of a slick.

The Royal Canadian Mint has served the Dogwood Initiative a cease and desist order after the non-profit group distributed decals to stick on the coin's loon design.

The decal covers the coin and has horizontal lines depicting the water in black to create an illusion that the bird and its surroundings are coated in oil.

The Dogwood Initiative hopes the campaign warns Canadians about potential federal support for proposals to allow oil tankers along B.C.'s north coast, including Hecate Strait, Queen Charlotte Sound and Douglas Channel.

Letters sent to the group say the dollar demonstration violates trademark and contravenes the Currency Act by using Canadian coins for purposes other than currency.

The group says the letters warn of possible summary convictions, fines and imprisonment.