I bought the
Regatta trousers in
@puffinbilly 's link, but from a different retailer so I could get an equally cheap Regatta rain jacket as well.
Both items look OK, and certainly good for the money.
'Isolite breathable and waterproof technology' it says on the label.
I haven't tried the waterproof claim, but breathable looks unlikely given the almost instant 'boil in the bag' feeling I had while trying on in the kitchen.
No worries, I shall be glad enough of both things when I next get caught in the rain.
Which is my next challenge - making sure the jacket and trousers are in my pannier when they are needed.