That's what I just said... Even without the presence of UKIP the Tories would win more votes by moving "right" on Europe/immigration/crime. Of course, the pre-Falklands SDP surge, 1992, Blair, and Cleggmania all seem to suggest that Britons are in search of "centrists," but YMMV.
None of things suggest that Brits are in search of centrists. Cleggmania was a non-event in the end, Blair won in large part due to anti-tory fatigue, it is dubious to say that Major was more centrist than Kinnock in 1992 except that Major and the tories were more familiar and the Pre-Falkands SDP surge had more to do with the fact that Margaret Thatcher and the Tories had spend 3 years destroying Britain's industrial base (1982 was pretty much the nadir of the late 1970s-1980s global recession) and Labour were an organizational mess. But whatever.
I'm not sure whether the Tories would win more votes if they moved to the right, especially as they are very much to the right on everything already. But whatever..