And there was me thinking I’d get a quick, straight answer on here…..
I’d certainly agree that in the first scenario the best and least contentious practice would be to pull over to the outside lane, overtake and then return to the lady lane.
In the other scenario though you would have to pull into the middle lane, slow to the middle lane drivers speed, wait for a gap in the outside lane, move into it, overtake and then move back into the last lane. This is more ‘dangerous’.
And for a final scenario, what about if the outside lane is also only doing 65mph, due to volume of traffic forced out there by the middle lane driver, but the inside lane is clear for hundreds of yards. Can you then legally keep doing 70mph and undertake both lanes of traffic, do you slow to 65mph and not undertake, or do you trg and join the outside lane of traffic adding to the problem?
This final situation seems very common, even on busy motorways.