Undertaking is a job entailing the preperation and presentation of dead bodies prior to burial.
What you're referring to is 'overtaking on the inside'
It is, other than one or two exceptional circumstances, illegal!
Plain and simple, if you do it, you're breaking the law, if seen you will be pulled aside from teh fact that you're putting yourself at a greater than usual risk.
At the end of the day 70mph in
the outside lane is what they are supposed to be doing.
No, it isn't.
The only lane on a dual carriageway or a motorway that you should continuously travel in at speeds around 70mph is the inside lane, the middle and outer lanes are overtaking lanes, they are for the sole purpose of passing slower vehicles, not for sitting in at any speed.
(excepting short stretches where a motorway splits and to continue on one motorway you select the middle lane until it feeds back into it's own dedicated road)
It's a sad fact that plenty of company car rep types hog the middle lane plodding on at 80 thinking this is perfectly acceptable. Unfortunately it's such a commonly occuring thing that unless someones causing a blockage or problem the police won't intervene and they let people continue leading to the frustration of some people deciding to overtake on the inside.
Like others, i've never experienced this, i've had drivers deliberately move over to the right and refuse to let me pass, I even had one sitting there in standing traffic shaking his head, 'no', after he'd ignored my throttle blips, headlight flashing and progressed to giving a beep of the horn, he was stuck in the traffic, I had room to filter, he didn't want me to becuase some people are mardy arsed tossers.