As a registered engineer i am supportive of some merchants not selling 'gas' fittings to non-registered but, i hope it doesn't become a 'closed shop' and that means lack of competition (back to the 70's!!), higher prices and effectively a restriction of trade. What about these scenarios;
A large national housebuilder negotiates low prices for bulk buying but, a merchant says, sorry your not competent to have boilers or gas fires?????
You need to get your car brakes done but halfords laugh when you can't prove your qualified and suggest they can supply a local garage only and not you?????????
Oh and by the way, no more heating controls, wiring centres, cable or fused spurs for you plumbers, only available to qualified electricians???
Or... are we all saying that car repairs and 230v electrics don't have any safety issues and are all DIY???