Services on some Tube lines are set to be disrupted by a 24-hour walk-out by train crew at two Underground depots.
Crews at the Bakerloo depot at Elephant and Castle in south east London and at the Northern line depot at Morden in south London have been instructed by their union, the RMT, not to book for any duty between 9pm on Friday December 17 and 8.59pm on Saturday December 18.
The action is over two separate disputes involving a drivers' health and safety rep at Elephant and Castle and a driver at Morden.
RMT general secretary Bob Crow said both disputes were "clear-cut cases of victimisation on the grounds of trade union activity".
London Underground said only 19% of RMT's Northern line staff had voted for strike action, while it was "utterly outrageous" for the union to threaten action "in support of someone dismissed for a serious breach of safety rules on the Bakerloo line".
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