METROPOLITAN Tube line services were severely disrupted yesterday due to a one-day walkout by train drivers based at a Rickmansworth depot.

The 77 strikers, who are members of transport trade union ASLEF, took action in support of a colleague who was removed earlier this year from train driving but was allowed to continue in a platform-based role.

Acting general secretary of the union, Simon Weller, said the disciplinary action came after an accident at Moor Park station in November 2009 in which a door closed on a female passenger, injuring her leg, and she was left on the platform.

Mr Weller said: "It was a regrettable incident, of course, but the sanction is totally unfair in this instance. The driver had 33 years' unblemished service and he was not at fault.

"The problem was caused by safety deficiencies, especially concerning mirrors, which we had reported regularly to management.

"It is utterly wrong that one of our members should be disciplined because management failed to react to our warnings.

"Our members are perfectly entitled to react against this flawed judgement, which is why 90 per cent voted in favour of the action."

The 24-hour industrial action that began at 12.01am yesterday forced Transport for London to introduce a 'special' timetable that affected the running of trains on the line.

The Chesham shuttle, which solely connects Chesham with Chalfont and Latimer, did not run and instead a through service calling at all stations to Wembley Park was laid on.

This had a knock-on effect on the frequency of trains on the rest of the line.

Services on the Piccadilly line were increased between Uxbridge and Acton

Town during peak hours, while Chiltern Railways made extra stops where possible.Nigel Holness, London Underground service director, said: "We are disappointed that ASLEF has balloted for strike action.

"They have stated this is over a breakdown in industrial relations but have provided no evidence to support this, nor have they raised any issues.

"We are at a loss to know what has led to the strike other than a disciplinary case of one driver who has been temporarily re-graded following an incident in which his failure to follow safety procedures led to a customer being injured.

"We will not compromise on safety, and we would urge ASLEF to call off this completely unnecessary strike action immediately." * What do you think? Email reporter Siba Matti or post a comment online.