Hello, welcome to the website. My name isXXXXX can assist you with this.
Do you know whether they have planning permission to use their premises as a car workshop?
I don't know but I very much doubt it as, to my knowledge, they don't own the property. These are flats above some shops in the middle of a residential area in a village. The garages are behind the shops and I believe they are owned by the shop owner who also owns the flats
Okay. Well it has to be worth a call to the council anyway, because if they don't have permission, then they can come and take enforcement action with a view to closing them down.
You should check the land registry too and see whether their title has any covenants affecting the things they may use it for.
Sometimes, you have covenants that say it can only be used as a single private dwelling house etc.
If that appears, they you may be able to rely on this to prevent them from using it as a garage.
You can do that the http://www.landregistry.gov.uk website.