The man who served as deputy to rail union leader Bob Crow for 12 years was elected his successor after the sudden death of the union legend this year.

Mick Cash, 54, beat four rivals yesterday in a ballot to become the new general secretary of the Rail, Maritime and Transport union.

Mr Cash, who has been a member of the RMT and its predecessor National Union of Railwaymen for 35 years, stood in as acting general secretary after Mr Crow died in March. He is more moderate than his rivals for the post, but regarded as a vastly experienced negotiator who has won some hard-fought agreements for union members.

He has spent all his adult life in the railways, working as a railway engineer before becoming a union official.

Mr Cash said: I am proud and honoured to have been given the enormous responsibility of now taking our fighting and militant union forwards, six months after the bitter loss to the Labour movement of Bob Crow.

"Let me make this clear. There will be no deviation from the industrial, political and organising strategy mapped out by RMT under Bob's leadership. Our fight on pay, jobs, working conditions, pensions and safety continues on every front and in every industry where we organise members."

Phil Hufton, London Underground's chief operating officer, said: "I'd like to congratulate Mick Cash on being elected general secretary of the RMT Union.

"I look forward to continuing our working relationship going forward, I'm sure we have similar interests for the future of London Underground."