I always thought it was illegal. I know when I broke my wrist and drove myself home with a cast on, the doctor went ballistic and said if the police had caught me I would have been reported for driving without due care.
I'm not 100% sure of the legality of this. Hopefully someone more clued up than me will answer you.
plus think of it laterally - if you are involved in an accident and are trapped, it will be more difficult for you to get out of the car, because of your limited mobility.
your consultant should have advised you about when you are able to drive again. Personally, i dont see how you can drive with the foot in plaster because you cannot feel the pedals
According to DVLA and CPS rulings. Driving with an impairment such as arm or leg in plaster or impaired sight should be considered an example of dangerous driving