In case you still look here according to the rule book. For socket outlets A minimum of 2.5mm is required (exception: Smaller conductors may be used on subcircuits supplying socket outlets, based on their suitability, in accordance with this standard, and taking account of voltage drop, current-carrying capacity and reliability of connections.)
1mm twin and earth for your lights are fine, it depends on your load for the power circuits but I'd probably run 2.5mm just to be sure, and for the submains 6mm would be more then ample.
1mm twin and earth for your lights are fine, it depends on your load for the power circuits but I'd probably run 2.5mm just to be sure, and for the submains 6mm would be more then ample.