I've been advised that 2.5mm2 cabling isn't recommended, and to go for up to a 10mm2 cabling setup (even with a 15A circuit) - is this correct?
You can use this calculator to independently check it - provided you correctly define the installation conditions:
Cable Size Calculator AS/NZS 3008
Cable size calculator for current rating, voltage drop, loop impedance, earth cable and short circuit, based on Australia and New Zealand standard AS/NZS 3008.
www.jcalc.net
How long would the cabling run be? 32A with 6mm conductors (for sheathed cabling touching a surface, or in conduit in air) would be good for a run up to 28 metres. 10mm conductors carrying 32A would be good for up 50 metres. 10mm conductors are very hefty and difficult to run.