Thanks Matt!
So an update for everyone who gave advice on this.
It turns out that the chain adjusting mechanism on one side was quite loose and so the wheel was not entirely straight, it has been dealt with by a nice man with spanners
and will now brake in a straight line! which is always good!
And a track day has been sorted.....cadwell here I come!
Thanks to everyone who commented on this especially Fast Jock who came over and checked the brakes out for me.