Piccadilly Line Tube drivers to go on three strikes
Tube drivers will stage three 24-hour strikes over a "breakdown in industrial relations", union bosses have warned.
About 400 drivers on the Piccadilly Line will walk out before Easter on 23 March, then on the 19 and 21 April.
The Rail, Maritime and Transport (RMT) union said 85% of the members polled voted for strike action.
The London Underground line carries 600,000 passengers a day on average and is the only Tube service to Heathrow airport.
The union said several issues had led to the call for strike action, including concerns over the "ageing Piccadilly Line fleet", which have "left drivers in a vulnerable position".
'Bullying, harassment and intimidation'
The Piccadilly Line has some of the oldest trains on the network known as "1973 stock".
RMT general secretary Mick Cash said: "The wholesale abuse of procedures and agreements by management on the Piccadilly Line is rife and amounts to the development of a campaign of bullying, harassment and intimidation that the union will not allow to continue."
Transport for London urged the union to continue discussions with the operator.
Operations director Pat Hansberry said: "It is disappointing that the RMT is once again threatening unnecessary strike action without seeking to resolve these local issues with us first."