I know that (and I don't do it) but I am puzzled why you should have to move to lane one if you are travelling at the legal maximum in lane two. You are not holding anyone up who is also obeying the speed limit.Like many here most of my miles in the van are from driving abroad. In my opinion the worst drivers are on the M25 and M27, and the worst surfaces are probably in Belgium.
...because you should keep left unless overtaking...
I knew this would raise a few hackles but no-one has satisfactorily explained the reasoning behind this