A paediatrician bullied his colleagues as if he were King Arthur and they were his knights of the Round Table, the General Medical Council has heard.

Dr Anthony Cronin allegedly sent staff at Plymouth Hospitals NHS Trust a series of "rude and inappropriate" poison-pen emails.

In one message he criticised a fellow doctor's treatment of a patient as "tantamount to child abuse", the GMC heard yesterday.

Others – which were copied in to other staff – threatened to tell a patient's parents to sue the Trust and criticised a committee's "tick-box mentality".

But, the GMC was told Dr Cronin had been frustrated at the lack of resources for child care services in Plymouth.

Gary Summers, for the GMC, said Cronin had engaged in "bullying, harassment and rude and inappropriate behaviour".

"The trust received many complaints in relation to his behaviour and advised that he was confrontational, verbally aggressive, intimidating and rude on many occasions," he said. "He sent inappropriate emails to directors, management and colleagues which undermined their ability to do their jobs.

"Making allegations in email and copying in many people is one of the key parts of this case.

"The fact of the matter is these are very serious allegations.

"One has to put oneself into the position of the people working in the trust around this doctor at the time.

"At this time, he was behaving disgracefully, almost as if he was King Arthur and those in management were his knights of the round table.

"His conduct was serious, significant and sustained."

The GMC heard Dr Cronin was sacked for gross misconduct in 2009 following a series of complaints and was now working in Poole, Dorset.

After being told of the introduction of a new type of paperwork at the Plymouth Hospitals NHS Trust, the GMC heard Dr Cronin angrily replied by saying the scheme was "suggested by those who are devoid of any experience" and "hasn't been thought through".

He also copied in other paediatricians and child ward managers.

Dr Cronin added: "Some committee with a tick-box mentality had to justify themselves without thinking of the consequences."

When a member of staff, known as Ms B, told him his comments were "offensive and derogatory", he retorted: "Now, now, is all clinical feedback by clinicians struggling to get by in the real world 'derogatory and offensive'?".

In another message to a pharmacist, he threatened to tell a patient's parents to sue the trust, while in another he criticised a fellow doctor's treatment of a patient as "tantamount to child abuse", it was said.

One colleague "feared opening emails from him because they were always so horrible", the panel heard.

Brendan Finucane QC, defending, said Cronin was frustrated by dwindling resources for child care services in Plymouth.

"He had a major role in the development of child care services in Plymouth over 23 years," said Mr Finucane.

"During his time at the hospital, he was frustrated because resources were being eroded. He fought his corner tenaciously, and he has accepted sometimes it was inappropriate.

"He has been intemperate and he realises that. His intemperate behaviour was driven by his commitment to child services," said the QC.

Deciding against imposing a formal warning, GMC chairman Mandie Lavin said the panel had noted Dr Cronin's acceptance that, on occasions, he used inappropriate and intemperate language.

But she told him: "We consider the language and tone of many of your emails to have been inappropriate and unprofessional, and accept that these must have caused upset and embarrassment to others. We cannot condone such behaviour and would like to advise you that you should be careful in all your communications in future and ensure that you treat everyone with dignity, courtest and respect.

"You have apologised for your behaviour and regret that you copied your correspondence to a number of other professionals within the Trust. We have taken account of the stresses that sometimes exist in day to day clinical practice and the difficulties of balancing this with management responsibilities.

"The committee is satisfied that you are genuinely sorry and have taken appropriate steps to ensure that you never repeat such behaviour in the future."