In fact, there have been rumblings from retired generals and the like for quite a while now, but nothing has caught on. I doubt this will either as whilst it is clear to those who think about it that Parliament and the country were misled, there are plenty who are willfully blind about the matter. Also, the government has done a good job of obscuring the evidence. I might know with reasonable certainty that they attempted to mislead me, but I doubt I could prove it to a legal standard.

The other issue is that "impeachment" is a an old strange legal action in the UK, last used in 1806? I think and thus much less likely to catch the imagination of the public and MPs the way the word does in the US.

Of course, that's not to say that it's not the right course of action, all the other ways of dealing with a rogue Prime Minister are essentially unofficial.

However, Tony Blair is seemingly on his way out anyway, so it's unlikely that the majority party would want to risk a big embarrassment of any kind. They would rather let the succession proceed calmly.