GasSafe man told me they that they can only connect onto the output terminal of an existing FSU, not install a new one or even unscrew it - by law.
In that case, you might politely ask him, if he is so wildly "inaccurate" in his understanding of quite simple laws/regulations, why on earth might you consider him capable of having understanding of the much more complicated laws on "gas stuff"
Then go on to suggest that since he's now admitted that he is not competent to be working on gas stuff, you'd like him to grab his tools and leave - but before he goes, would he mind calling his boss to arrange to have a competent technician sent out.
Basically, if he is competent to be creating a circuit from the FCU onwards, then he should be competent (perhaps with a little reading) to work upstream of it.
I am unaware of any such law.
You wouldn't be because, as already said, there isn't one.
The politicians certainly have my sympathies in this situation, since they are constantly finding themselves between great piles of rocks and great piles of hard places - and, on balance, I reckon they're doing a pretty good job (even if there are some things 'which don't make sense') under the circumstances.
I agree - very big rock and very big hard place.
IMO we're overdue for someone (probably Boris) to simply come out and discuss the elephant in the room - if we don't get the economy running again quickly, that will cause deaths (perhaps more than the coronavirus itself) going forward. We already know that suicides are up, domestic violence is up, child neglect/violence is up, routine medical treatments are down, etc, etc. At the moment, IMO there's too much pandering to the "but we must keep up the lockdown because ..." brigade - just look at all the wailing over the relatively minor relaxation of the rules the other week. Are we already past the point where the general loss in life expectancy due to the worse economic conditions actually outweigh the possible losses from relaxing the rules somewhat quicker than they are being ? hard one to call, and people far more au-fait with the maths involved have already been looking at that.
I know my mother is going nuts - and she at least gets to see people every day (district nurse and carers), and we setup video chats with the family. I'm pretty certain that she'd take the attitude that she'd rather live a shorter but happy life than a long and miserable one - i.e. she'd rather take her chances than stay stuck at home - and I think my brothers and I would be somewhat resigned to that if she did catch it. As it is, the other week I took her to a hospital appointment, and on the way back called in at the local Booths - doing my best to stop her going up to everyone for a chat. Just one short shopping trip really made a big difference to her outlook - raised her spirits for a couple of days.