Prime Minister Noda has not quite staked his future on the consumption tax, but he has made this a big issue. If those measures don't pass, we would probably see the end of his role as prime minister. But then, we've seen a rapid turnover of Japanese prime ministers for some years now, and it hasn't had much of an impact on international relations or the policies the government has pursued. The prime minister can champion particular issues personally, and Prime Minister Noda has taken TPP as one of his causes as well. Still, I would suspect that even a change of government would not make much difference in the discussions over a Canada EPA.
On May 17th, 2012. See this statement in context.