I don't know how the law works in Canada, but here in the States you're only legally allowed to enter any intersection if you can clear it before the light changes. That's the whole point of the yellow light. It means you're not supposed to enter the intersection, but if you're there you have time to get out before the light changes. If there's a traffic backup in the intersection, you're not allowed to enter it unless you can clear it. Basic driver's ed 101 stuff here. Not many people (drivers, cyclists, peds) act like they know it, but it is the law, and I wouldn't be surprised if that's the law in Canada too. So no, you don't get to stay blocking an intersection just because you entered it when the light was green.