Peter Marks is a Co-operative lifer, and proud of it. At 17, the Bradford High School dropout took a job stacking shelves on the shop floor, before being trained for management and, eventually, winning the top job. Indeed, the only other “job” that Mr Marks admits he could possibly enjoy more would be drumming for the Rolling Stones. He goes some way to satisfying this ambition by playing in an amateur Stones cover band.

His loyalty to the Co-op has served him well and in 2002 he was made chief executive of United Co-operatives. Last year, he brought about the merger of United with Co-operative Group, putting him in charge of the world's largest consumer co-operative. It has an annual turnover of almost £10 billion, a membership of four million and employs more than 87,000 people. His perseverance has served him well, with the Co-operative the only bidder in the race for Somerfield — a company that Mr Marks has eyed since 2005.

Buying Somerfield would be a huge coup for Mr Marks. While the Co-operative spans five sectors as diverse as healthcare and car dealerships, it is for food retailing that it is best known and by which it is judged.

Like many others, Mr Marks has been fighting against the might of the superstore. When he joined in 1967, the Co-op had 25 per cent of the grocery business. That figure is now less then 5 per cent.

Mr Marks has reacted by abandoning superstores and concentrating on convenience stores and community supermarkets of about 10,000 sq ft. The idea is that while families will do their big weekly shops at Tesco, they will drop in regularly to Co-ops for smaller purchases.

Somerfield fits in perfectly with this strategy, as did the acquisition of five former Safeway stores in Yorkshire from Wm Morrison in 2005. Mr Marks readily admits that it was not the Co-op's philanthropic ideals RAF in private deal for mid-air tankers — “a business democratically run by members to meet their common needs and aspirations” — that attracted him as a teenager.

More than 30 years later, however, the 58-year-old knows what makes the business tick. “We are trying to sustain community life, because we have community stores. People identify with their local Co-op store, because it's their community shop. We need to build on that,” Mr Marks has said.