OPEC will be very grateful to the NDP and Greens if they can halt the pipeline.  More market share for them around the world, and they polute as much as they like to produce oil and products.  Nigeria wipes out entire towns with toxic waste and pay armed millitants to shut anyone up that complains.  That is where the NDP and Green parties prefer the oil comes from to supply the world.  Ideally, 3M barrels of Canadian oil comes off the market and is replaced by a boom of production by OPEC and other countries with no environmental standards.