I am sure I remember reading or seeing something on the BBC website a few years ago which led me to believe they had changed the law, hence my comments.
So, I telephoned the 'plod' helpline this morning for clarity on the overtaking/undertaking. It seems the key word here is discretion. The same rules apply as always where overtaking in the inside lanes to avoid congestion is justified if deemed reasonable due to circumstances. I think most of us have done this for sensible reasons. Overtaking at high speed, which seems to be the increasing trend, if considered dangerous at the discretion of the police, is punishable. Equally, travelling at a slow speed @55-60 in the middle and overtaking lane could also be considered dangerous at the discretion of the police, depending on the circumstances and therefore punishable. So, it seems my initial impression that they had changed the rule was incorrect. What we are seeing is the 'bending' of the rules. Sorry for any confusion. Let's just hope the benders do not kill anyone in the process.