Nick Robinson is Tory, I've been watching him for a few years now and he's always seemed more Tory than Labour, even in the Blair and Brown years.
To be fair, though, the TV correspondants are a lot less biased than the papers. I had the misfortune to read both the Sun and the Mirror during the election campaign (and the Star and Daily Fail too, on occasion) because of them being left in the canteen at work and nothing to do on my breaks, and they were so biased I couldn't believe it at times.