Boris Johnson accused Ken Livingstone last night of using millions of pounds of public money to bribe Tube maintenance staff into calling off a 48-hour strike that would have paralysed all lines just before the mayoral election on May 1.

More than 2,500 staff employed by Metronet, which collapsed last year, will receive free annual season tickets worth almost £1,800 each for themselves and their partners in a deal approved by Mr Livingstone.

The deal, which also includes the right to join Transport for London’s generous pension scheme, will be funded by passengers and London council tax payers.

The strike would have disrupted the journeys of the three million daily Tube passengers and been highly embarrassing for Mr Livingstone.

Mr Johnson said: “This is an election bribe to keep the unions sweet a fortnight before the election.” The Conservative mayoral candidate called on Mr Livingstone to explain his involvement in the discussions on Friday with the Rail, Maritime and Transport union.

He added: “Did Mr Livingstone order his transport adviser to stop the strikes no matter what the cost? If so, this will be yet another breach of the election rules.”

A spokesman for Mr Livingstone said: “The mayor remains responsible for the government of London until the election. He, therefore, is in constant contact with TfL, which he chairs, and was naturally kept fully informed of every stage of negotiations with the RMT.”

Bob Crow, general secretary of the RMT, said late on Friday that he would recommend to his executive that the strike be called off.

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