I'd missed the progression of this thread so I'll just try to catch up a bit!
Most mobile work, even servicing could be described under catagory five as "necessary" - "my brake light was blown and so it was repaired by this nice mobile mechanic as he serviced the car. I did not want to drive it as it would be against the road traffic acts to do so and I wanted to ensure that there was nothing else that would render my driving the car illegal which is why I had the service at the same time".
So hopefully we are all covered on that basis but how about the view of an arsey council officer - "this car can be towed and so it is not necessary to repair it here, particularly as the tow would be covered under his AA breakdown policy". So maybe not strictly covered after all - it may be cheaper to do it mobile but it isn't necessarily necessary!
As far as the insurance or profit question goes for the rescue companies, again you could take either view but as I'm sure that none of the major breakdown companies are about to ban their patrols from selling batteries and other parts there is still clearly a profit element in there somewhere.
I would on a wider note agree with some of the comments made that this is only going to be enforced in cases where there is a complaint and even then, only after a series of warnings. Hopefully, we are professional enough to avoid any such complaints and they will only be made against the dole dossers that always make a nuisance of themselves in the same street. One thing that council officers don't want is a bunch of extra paperwork.
It may be that in theory we are breaking the law but it does seem that it is a matter of interpretation, so maybe not. Either way, who hasn't done 80mph on a motorway or used a mobile phone, lit a cigarette or adjusted the radio whilst driving? These things are all strict breaches of the law. My greatest concern is that by contacting MPs, questioning councils and the like, we are putting our heads up and shouting "look at me I'm breaking the law" and I'm not sure that's very wise.