is it ok to have a dryer in an extension lead, which is plugged into a fused socket?

There is N O SUCH THING as an extension cord rated for permanent use. There is NO excuse for not having a dryer outlet within ONE foot of the dryer.

A dryer runs off a 220 plug, So, no

yes, as long as it's the correct type of fuse, there aren't many other things plugged into the same socket, and importantly the extension is not coiled up.

I would not use an extension. No one even asked it this was a gas or electric drier, Another item that they missed was how long. The longer the cord, the greater the voltage drop. Its funny how this works. Lower voltage the higher the amps will be.

Yes. But the extension lead MUST be rated at 13 amps. (UK answer). If it is a cassette or reeled extension lead unreel it or it may well get hot and melt.

Yes - you will need a 13A fuse.

Uncoil the lead otherwise is will act like a solenoid - and melt the insulation.