Bill Grimsey, chief executive of the UK's Big Food Group, has reportedly accused the UK's competition watchdog of failing to protect convenience stores as part of its inquiry into the takeover battle for supermarket chain Safeway.

Grimsey said the Competition Commission should have defined the grocery retail market as two separate sectors: convenience stores and out-of-town supermarkets, reported the Times.

"It is allowing people like Tesco to enter the convenience store market and grow market share. They are large enough and it is up to them to exercise their powers to stop it," he was quoted by the newspaper as saying.

Grimsey reportedly indicated that he would seek further intervention from the Office of Fair Trading.