Harper and the Notwithstanding clause

Many bloggers and commentators are speculating that Stephen Harper would invoke the Notwithstanding clause re SSM despite his public commitment not to do so.

Harper has:(1) committed to have a free vote on SSM and (2) to not use the Notwithstanding clause. If he has a free vote with a minority government it will not pass. Game over. If he had a majority(highly unlikely) and the vote passed then he would have to find a way to do it without using the Notwithstanding clause, or let it go. I don't believe that he would invoke the Notwithstanding clause, having said publicly that he wouldn't. While I strongly disagree with his position on SSM (and other social issues for that matter), I believe that, unlike Martin and McGuinty, he is trustworthy. Ironic, isn't it, given the Liberal scare-mongering on this issue? It will be a pity if the Liberals slip through to another minority in spite of their scandalous record because they can successfully exploit this one issue to their advantage.