The independent retailer fighting to stop Marks & Spencer from calling its new convenience stores Simply Food has vowed to battle "to the bitter end". Richard Jackson, md of northern based Simply Food, which has been trading under the same name since 1986, delivered the warning as his giant rival this week opened the third of more than 20 stores planned under its new format. M&S has applied to the Patents Office to register Marks & Spencer Simply Food' as a trade mark. But Jackson said he was writing to the chain's bosses to warn them that he will contest them all the way. Jackson, who runs four stores in Sheffield and Rotherham, said: "Simply Food is my company's name and I will not let anyone else use it." A spokeswoman for M&S said it was free to register Simply Food as a brand as Jackson had failed to do so. {{NEWS }}