The two forecourt sites have traded as Budgens for several years, but the local market dynamics changed when Musgrave purchased the Somerfield supermarket in the town and started running it as a corporately owned Budgens store.
Jonathan, who is well-known in the town, and the Budgens brand were subsequently criticised in the local newspaper for removing the choice available to shoppers in Chatteris, forcing the retailer to reconsider his trading partner. Blakemore's now supplies the sites.
He told C-Store: "Because of my customers' reaction, I felt I had no alternative but to make the change. Beyond that I don't wish to comment further."
Jonathan owns three other stores in the area and he confirmed that these would stay as Budgens outlets.
A Musgrave spokeswoman commented: "Jonathan is a valued retail partner and we're delighted that we still have that business relationship."