Tail lights (both sides) aren't working on my son's Ka.

Front sidelights and dash ok, so apparently it's not a fuse.

Brake, indicators, and reverse lights ok - so it seems unlikely to be a corroded pin on the multi-connector.

Possible fault with stalk-switch?

Suggestions appreciated - please and thanks.

 

The stalks do fail causing this, I would expect this is your problem.

 

Thanks.

Is it likely that it'd just fail to the rears though - and not all the sidelights/

I guess the easy check is to temporarily short the appropriate wires together - but I've no idea which.