If he is a contractor for Tesco, as you have stated, you should raise a complaint with the store manager, or whoever the senior staff manager is there at the time and have him moved to a more appropriate parking place.
If he is ultimately working for Tesco it is down to them to resolve the situation, not you, or any of the keyboard warriors commenting from afar.
Unfortunately their are dickheads in every walk of life. I had a local council van driver parked half on the pavement the other day with the engine running for over an hour while he slumbered in the cab during what was definitely the working day. A couple of time stamped photos along with a brusque e-mail and he's not catnapping, parking on the pavement or leaving his engine running anymore, certainly not outside my place.
My natural response at first would be to confront him and verbally tell him the errors of his ways, but the reality is that it would achieve very little and if past "encounters" are anything to go by I'm not the best in keeping my temper in check especially if the other individual is a know-it-all gobshite.
A photo or two with a clearly marked registration number so the driver cannot refute the claims along with a pithy e-mail usually does the job. It ain't that hard.