He was once the leader of Britain's doctors. Now James Johnson stands accused of horrific surgical blunders. So did his status go to his head?

The former leader of Britain's doctors once told a meeting of the British Medical Association (BMA) that he was a man "not much troubled by self doubt".

Last week, the character trait that James Johnson highlighted as he sought re-election as the chairman of the BMA may have led to his downfall. The 64-year-old vascular surgeon – who drove a Bentley, sent his children to top public schools, and held the top job in British medicine – appeared before the General Medical Council (GMC) accused of amputating limbs unnecessarily, accidentally stabbing a colleague in the forehead with a needle in a fit of fury, and behaving in a manner that was a "caricature of surgical arrogance".

For any doctor to face disciplinary charges of this kind in a public hearing would be a disaster. But for Mr Johnson – a surgeon of previously high repute who was the public face of the BMA for four years – it marks a catastrophic fall. He is accused of misconduct in relation to 14 patients on whom he operated between June 2006 and January 2008, at least one of whom died.

In one operation on a 69-year-old woman in July 2007, he was described by counsel for the GMC, Andrew Colman, as moving from "initial irritation, through increasing exasperation to outright aggression". Towards the end of the operation, as he was closing the patient's abdomen, he accidentally struck a house officer on the forehead with a needle and then ignored warnings of colleagues about a missing surgical clip which was still inside the patient's leg.

Mr Johnson's behaviour reflected "a caricature of surgical arrogance that was out of place even decades ago, other than through the lampooning lens of cinema comedies", Mr Colman said. He was also accused of "over-operating" and using "outdated" techniques. In two cases he car

ried out amputations without considering less radical surgery and in seven others he performed surgery that was "inappropriate", "not surgically indicated", "not in the patient's best interests" or where he had failed to consider alternative approaches.

For almost half of the 19-month period that the GMC is investigating, Mr Johnson was chairman of the BMA and it was suggested he suffered from "conflicting pressures". He operated one day a week and was based at Halton Hospital, Runcorn, but was also required by the North Cheshire Hospitals NHS Trust to work at a hospital in Warrington, which he resented.

His arrogance was frequently commented on and he was forced to resign his BMA post in May 2007 after misjudging the anger within the profession over the Government's botched attempt to reform medical training. But what shocked those who knew him was he had allowed this arrogance to – allegedly – affect his conduct in the operating theatre.

One said: "He was very dismissive of people whom he regarded as intellectually inferior. He regarded his arrogance as a strength, that someone prepared to confront opposition to get things done made a good leader. But it was a shock to hear the allegations about his clinical performance. I had always assumed he was a highly competent, extremely well respected surgeon."

Another was taken aback by the scale of the charges: "He told me that he was facing investigation by the GMC over a patient whom he had failed to visit following surgery. But when the charges were published, they were much more extensive. He was arrogant and made a virtue of it. I remember an after-dinner speech in which he told stories entirely about himself."

In 1998, Mr Johnson, then chairman of the Joint Consultants Committee of the Royal Colleges and the BMA, proposed performance measures to identify poor doctors before they came to the attention of the GMC. "We are going to put in place something to reassure patients that their doctor was not just an excellent chap when he qualified 20 years ago, but that he is still an excellent chap and has kept up to date," he told the BMA's annual consultants conference. He may be regretting this week that such a system is still not in place.

Mr Johnson denies the charges against him. The GMC hearing is expected to continue until November.