When using terms like right wing and left wing it's important to appreciate within what context they are used. A right wing Labour supporter and a left wing Tory would have very much the same political philosophy, and it would be reasonable to call that centrist. But of course it would not be centrist Labour or centrist Tory - a centrist Tory would be well to the right of a right wing Labour supporter or left wing Tory.

Keith comes across as a centrist within the wider political spectrum, and a leftish Tory but clearly within a Labour context he would be well on the right.

It's a pretty elementary confusion. I think in the kids book I read there was the shortest giant in the world, and the tallest giant, and they were the same height.