Was in a B&Q warehouse yesterday, and hanging on the end of one of the racks in the paint aisle were some (I quote) "do it yourself gas fire fitting kits", containing various brass couplers and a bit of copper tube.
Each packet had a large notice on it, "gas appliances should only be installed by a corgi registered engineer".
Rather bizarre I thought, when the plumbing aisle is full of dire warnings about DIY gas work being illegal.