Randomisation will be stratified by site and entry therapy (monotherapy OR dual therapy which includes metformin plus pioglitazone or metformin plus either a sulphonylurea or repaglinide) resulting in 6 groups using a variable block size of between 4 and 6. Participants will be randomised 1:1 to metformin + Canagliflozin (Invokana™) or to metformin + a sulphonylurea, or continuation of their sulphonylurea, repaglinide or pioglitazone.