Dates for further strikes on the London Underground have been announced after Night Tube drivers voted overwhelmingly in favour of industrial action.
The RMT (National Union of Rail, Maritime and Transport Workers) has announced two sets of dates for the strikes.
Night Tube staff will not book on for duties on April 8/9 and April 29/30.
It will affect the Central, Jubilee, Northern, Piccadilly and Victoria lines between 8.29pm on April 8 until 8.30am on April 9 and from 8.29pm on April 29 until 8.30am on April 30.
The strikes have been announced after Night Tube drivers voted by more than 96% for strike action, because of a “block on career progression which has been imposed by London Underground (LU)".
The dispute is over a policy that prevents Night Tube train operators from moving into vacant full-time positions for a period of at least 18 months, while other staff, including Night Tube station workers, are eligible to apply.
According to the RMT, London Underground has also advised that Night Tube drivers do not get overtime pay until they exceed 35 hours a week, but they are not compensated for late finishing because they are contracted only 16 hours.
RMT general secretary Mick Cash said: "It is outrageous that London Underground have decided to discriminate against their Night Tube drivers.
"This is a senseless and damaging policy that picks out one group of staff for negative treatment and of course the drivers are angry and that is why our members have voted overwhelmingly for action.
"Our executive has now considered the current position and has concluded that we have no option but to move forwards with the announcement of these strikes.”
In response, operations director for London Underground, Peter McNaught, said: "Night Tube services have been running since August last year in line with agreements reached with the unions.
"We’ve met with the unions to discuss and resolve the new issues that they have.
"We have invited the unions to more talks this week and I encourage them to continue discussions with us rather than threaten industrial action."
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