The law will be pushed through. It will go down that they tried to abolish prostitution. If the SCC tosses it out, they will say they tried and are now forced to go the other way. By that time they will call an election and make it an issue. Then if they get back in they'll say, "See? Canada wants it." And pass another more stringent law. If they don't get in they'll be able to say the winning party are whore lovers and that the tail wags the dog.
I'd rather gov't keep their damn morality bullshit out of the laws and do what they were elected to do. Pass laws that protect the weak and let those who choose it be on their merry way.