Firebrand leader says he is proud union stood up to ‘wholesale attacks’ on rail industry by Conservative party

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Mick Lynch has said he will retire as general secretary of the RMT union, after four years during which he became perhaps the most recognisable presence on picket lines amid the biggest rail and tube worker strikes for decades.

The National Union of Rail, Maritime and Transport Workers (RMT) said it would appoint a new general secretary in the first week of May. Lynch, 63, would remain as general secretary until then.