Frankly, my guess is that he still gets to Parliament but remains a backbencher. The interest would be how Gordon Brown handles becoming PM in 1997, and what happens with Cherie Booth's career now that she remains unmarried or has a different husband.
Well, his father was a Tory, so I guess it's possible.
Brown becoming PM isn't unlikely, but without Blair a few more options spring up- you have to understand that without Blair, there will be a variable host of butterflies within the Labour Party during the 1980's that may end up with Kinnock winning in '92 or Brown's political career fizzling out before he can make the big time and being replaced by one of the other young men of tomorrow he knifed on the way, or even the modernising faction taking a different path without his guidance (Clause IV may never be abolished, for example).
Without Tony, though, Cherie would likely end up in Parliament and at somepoint find herself on the frontbench, likely in the Home office or as the Attorney General.
Even assuming he has similar views to OTL, he was ambitious enough to at least get a frontbench position, he might even get a cabinet role in the Major ministry, who governed in a more centrist manner anyway.
No, it wasn't, it was explicitly a centre-right Government; a Blair who is still cribbing the SDP would not find a place in a Cabinet like Major's because he was too far to the left for them.
Not to mention the obvious that a Blair who is in the Conservative Party is
not going to be a centralist, he'll be a Thatcherite and one of the young yes men she surrounded herself with as she became detached from political reality.
If Brown is in all probability leader in this TL, then Portillo would keep his seat, the Tories would make more headway in 2001, and 2005/06 would be a close run thing either under a continued Portillo leadership or a later Hague.
Ignoring the butterflies, of course, Brown becoming leader is a likelihood in this scenario, though there is a question to what effect Blair had on Brown's ambitions in 1992 and 1994.
If they still lost, then Blair might be touted as the next leader, or he might back someone like Cameron who had the youth and new thing going, but the better results post 1997 might strengthen the right enough to prevent them losing control of the leadership. In any case, Blair probably ends up as a cabinet minister by 2010.
He'd end up Foreign Secretary.
And was Cherie's career particularly affected by her husband's? Im unsure whether she would try for parliament more than she did in this TL, so that is probably far too personal a question to know for sure.
Blunt answer is they'd never have a relationship if Tony's a Tory.