Hmm... I'm afraid this guy doesn't seem to have a good technical grasp of what's going on here. Gary, everything you've posted there is true, but it seems he either doesn't believe you or just doesn't understand what you're trying to tell him. Feel free to copy any of the following over into the discussion.
Plugs? they're either 2A or 3A or 5A. A special power circuit socket might be 13A.
There are no 3-amp sockets in Britain. 2A sockets were once quite common for lighting, but they're pretty rare these days, and they're so small that there's no way you could force a Continental plug into one anyway. The old British Standard 5A sockets will
accept a Continental two-pin plug, although it was not designed for this. You're most unlikely to find an outlet of this types in any modern hotel, office building, etc., except as a shaver outlet in a bathroom.
If by "consumer unit", you mean "fuse box", I assure you they're fused at the ampage appropriate to the circuit, and while I haven't see the wiring of many UK houses, I have seen the wiring of the few I have seen for many many years. I.e. each individual circuit will have either a 3A or 5A or 13A fuse in, at the fusebox.
If the power cord blows, it blows. But that won't happen because it will be on a circuit that is fused at well below 7-10A. Only a few circuits are fused at 13A, which is the only standard that is above that.
Sorry Sir, but you are quite simply wrong. 3A and 13A fuses exist only for fitting in plugs -- You won't find them at the distribution panel.
The modern BS1363 (rectangular pin) sockets may be on radial circuits fused at 20 or 30A or on 30A (32A if a modern circuit breaker) ring circuits. Most are likely to be thr latter.
Quite simply, the British ring circuit, now over 50 years old, relies on the 30 or 32A protection at the panel to protect the cables in the house. Every plug used on this system is fitted with its own fuse, which may be a maximum of 13A.
The sockets and plugs are rated for 13A maximum, but that does not mean that the circuits to which these sockets are wired are rated at only 13A.
If you jam a Continental plug into a British 13A socket, the chances are that the cord will be protected by just a 30A fuse.
I suppose you are going to tell me that the line blowing is a fire hazard?
That's exactly what he's telling you. Yes, in the event of a severe overload the cord may just burn out and cut power. But the point is that without the protection of the fused plug, you could have a #18 line cord connected to a circuit with just 30A over-current protection. It could just as easily smolder away, melt the insulation and start a fire.