The only reason I can see for this, is his party confidence level has decreased, and he's on the verge of a vote of No Confidence. But, not being a Brit, I can't say how he's doing politically.
John Burton, one of Mr Blair's closest friends and political allies, said: "He has spoken to me about it, and as far as I know he is not going to stand."
Mr Blair, MP for Sedgefield, has already said he will quit Number 10 after serving a full third term.
But Downing Street played down reports the premier had told friends he wanted a "clean break" with politics.
Full story here, and many other places http://news.bbc.co.uk/1/hi/uk_politics/4737927.stm