People will just travel to pubs and shops that are open. This will not work.
The parts of Leicester that are being hit hardest by the virus are predominately Asian, so they're less likely to be desperate for a pint.
You would hope that a majority of the population will see that people from Leicester are currently five to ten times more likely to be admitted to hospital with COVID than most other areas and take it seriously. Plainly a, probably significant, minority will do as they please, but you can't legislate for stupidity ( well, you can, but we don't have the police to enforce it ).