I'm not sure that makes him not right wing, surely that just means he wasn't the kind of right wing that succeeded in the political landscape of the UK in the past 20ish years? His voting record is generally in favour of less regulation (outside of a few issues), lower taxes, military intervention, isolation from the EU. He's pro-environmentalist, but that hasn't always been an exclusively left-wing thing. Similarly, anarchists and Marxist-Leninists are both left wing, even if they wouldn't necessarily get along well in a single political party together