A Thomas Cook Airlines captain has accepted an apology from the company after being sanctioned for refusing to fly due to claims that he was suffering from fatigue.

The airline also gave assurances that it remains committed to passenger safety.

Captain Mike Simkins was suspended for six months and threatened with dismissal after refusing to fly a Boeing 767 with more than 200 passengers due to fatigue.

Simkins took the case to an employment tribunal which unanimously found in his favour and against the airline.

Thomas Cook said there was “no point” when he was expected to fly while fatigued and the tribunal hearing came about following a dispute with his superiors.

Simkins took the “difficult decision” not to fly after three early starts in a row, including one 18-hour day, and what would have been a 19-hour day to follow, his union, the British airline Pilots Association, said.

Thomas Cook’s own fatigue monitoring software showed that because of the run of duties he had done, if he had flown his rostered flight he would have landed at the end of his duty with a predicted performance loss that would have been similar to being four times over the legal alcohol limit for flying, according to the union.

Balpa head of flight safety Dr Rob Hunter said: “Not only is it reasonable to refuse to fly when fatigued, it is absolutely necessary.

“In fact, the law states that a pilot must not operate when fatigued, or likely to become fatigued. Captain Simkins should have been praised by Thomas Cook for reporting his fatigued state as required by law, not disciplined.

“Fatigue is a major threat to flight safety and a good, open safety culture is vital in ensuring that pilots and other staff members feel able to report fatigued and not put lives at stake.”

The union’s general secretary Brian Strutton added: “Captain Simkins should be commended for taking this matter up and seeing it through to its conclusion. I am also pleased that Balpa helped fund Captain Simkins’ legal battles, and provided substantial expert and staff support.

“Tackling fatigue remains Balpa’s number one flight safety priority and we will continue to work with airlines to do that where we can, and challenge them using any means necessary when we can’t.”

A spokesman for the company said: “Safety is our highest priority at Thomas Cook.

“We have robust processes to ensure all the legal limits on flying time are met and we’d like to be clear that at no point was Captain Simkins expected to fly while fatigued.

“However, there was a disagreement between him and his managers about his conduct which led to the tribunal proceedings. We have accepted the findings and apologised to him for the hurt and distress that was caused.”