Hi All

Just to follow this up and let you know what we ended up doing.

To start with we had 6mm2 TPS in the wall going back to a 32A breaker, for our old oven.
Electrician simply ran another 6mm2 TPS in parallel, going to a 2nd 32A breaker, on the same phase, giving 64A capacity in theory.
Then he used a PDL (I believe it was) double pole switch, and job done.

As per Table C4, it was only required to do 40A, however the electrician said the last thing anyone wants is on Xmas day or something when the oven is cranking and full, for the breaker to go all the time, unlikely but also undesirable.

Anyway, all solved and working nicely.

Thanks everyone for the discussion and information, it really is appreciated and I have learn a lot from you all.