The identities of the doctors warned last year can be made public thanks to a Freedom of Information request by this newspaper. Warnings are published on the GMC register, which lists doctors by name and registration number, but using this to find out who has been warned and when would take a very long time.

Last night, campaigners accused the GMC of ‘going soft’. Katherine Murphy, the chief executive of the Patients Association, said: ‘The GMC is there to protect patients.

It must never compromise their safety by failing to deal with serious breaches of professional duty and trust in an appropriate manner.’

One of those who received a warning for missing a cancer case was Stockport gastroenterologist Navneet Ahluwalia, who was asked to examine a female patient with ‘significant abdominal symptoms’.

The GMC stated: ‘Despite test results that indicated the need for further investigation, Dr Ahluwalia wrote to the patient’s GP stating “we are not dealing with cancer” and that the results were ‘‘normal’’.

This was incorrect.’ The patient was eventually diagnosed with bowel cancer ‘after a significant delay which could have affected her prognosis’.

The GMC did not say whether the patient lived or died.

Bolton GP Dr Anton Kiss was warned for indecently exposing himself to two women at a Christmas party and smoking cannabis.

Dermatologist Dr Hari Narayana received a warning after trying to pick up a prostitute in the street.

And surgeon Munir Abdullah Ali was warned after throwing a scalpel in an operating theatre at Royal Oldham Hospital in Greater Manchester.

GMC chief executive Niall Dickson denied a warning was a ‘let-off’ for a doctor.

He said: ‘We take very seriously our duty to hold doctors to account if a patient in their care is harmed, or other serious concerns are raised about them. These cases are often complex, involving a range of issues.

‘We investigate thoroughly before coming to a decision. Warnings sit on the doctor’s record for five years and are publicly visible on our website.’