A 24-hour Tube strike followed Mr Barrett's dismissal

Chris Barrett's sacking prompted a 24-hour strike by the Rail, Maritime and Transport (RMT) union last November.

Mr Barrett, 30, said he had been advised by a therapist to take exercise to strengthen his ankle but he had got bored with the gym.

London Underground (LU) has said it will appeal against the decision.

Mr Barrett lost his �32,000-a-year job when he was seen leaving a sports centre by LU investigators.

We believe we acted fairly and responsibly in dismissing Mr Barrett LU spokesman

The driver, from Hackney, east London, had told the tribunal he did not want his job back because he had "lost confidence" in LU and has got a new job with a local authority.

Bob Crow, the RMT's general secretary, said on Friday the driver had been "vilified" by some sections of the media and labelled a "parasite".

He added: "The case raises some serious civil liberties issues including the release of personal information unconnected with the case and the use of closed circuit television footage."

But LU has said the tribunal found Mr Barrett "contributed to his own dismissal by 75% " and ruled on a technicality.

A spokesman said: "We believe we acted fairly and responsibly in dismissing Mr Barrett.

He added that the tribunal found LU "had reasonable grounds" to find Mr Barrett guilty of "acting incompatibly with his reason for sickness by playing squash".

The Tube's RMT members went on strike in November to support Mr Barrett, closing the Circle line and reducing service on the Hammersmith and City line.

Further strikes planned for Christmas Eve and New Year's Eve were called off.