Terry Thomas, managing director, said: "There's not a chance of his buying the bank. Neither the bank nor its parent are for sale, either now or in the foreseeable future. I have nearly 800 letters from customers telling me not to sell the bank and it's the same message from management and staff."
Mr Thomas said his correspondents were "without exception" against any sale, some stating they did not want "their" bank sold.
Announcing a 24 per cent surge in pre-tax profits for last year, Mr Thomas also launched a scathing attack on the wave of demutualisations, which has encompassed institutions ranging from the Halifax building society to the Norwich Union insurance group.
"It's a scandal of our time that this generation could raid assets built up over 100 years or more," he said. "There are other generations who had a greater social need. I'm thinking of the First World War and the Second World War. Why should it be this generation, for God's sake?"
Mr Thomas said he believed shortcomings in business culture were amplified by the values of the 1980s, foremost of which was "the misinformed idea that selfish behaviour... was in the public interest".
Profits at the bank, which is wholly owned by the Co-operative Wholesale Society, rose from pounds 36.7m to pounds 45.5m in the 12 months to 11 January. The period marked the first full year since the group added an ecological code to the ethical stance adopted in 1992 and updated in 1995.
The profits came on the back of a 27 per cent increase in retail deposits to pounds 2.4bn, double the level of five years ago. The bank claims a higher penetration of professional and senior managerial socio-economic groups than its rivals, with customers falling into social groups A and B representing 57 per cent of its credit card-holders, against an average of 34 per cent for the rest of the industry.
Despite higher lending, provisions for bad debts rose only slightly, increasing by pounds 1m to pounds 23.7m last year. The figures benefited from the write-back of provisions on loans to two failed property companies which have been sold.
Yesterday the bank produced a new "partnership report" which addresses the seven "partners" it has identified, namely shareholders, customers, staff and their families, suppliers, the local community, society at large and past and future generations.