About 15% of patients with diabetes develop diabetic foot ulcers. Nearly a quarter of these eventually need to have part of their lower limb amputated. A number of factors increase the risk of slow ulcer healing and the need for amputation: poor control of blood glucose levels; damage to nerves and loss of feeling in the lower limb; reduced blood flow to the foot; and bony deformities in the foot. It is thought that ulcers might heal better if patients had better glucose control and are treated with aggressive insulin therapy. However, many patients aren’t keen to start insulin. This study looks at the effect of intensive insulin therapy compared with standard oral diabetes medicines on ulcer healing in patients with diabetic foot ulcer. The study will also use a new form of imaging (laser speckle) to assess blood flow to the foot and its impact on ulcer healing.