London Underground workers are to strike for 24 hours on polling day over the dismissal of a colleague.
Members of the Rail, Maritime and Transport union (RMT) on the Central Line will walk out from 9pm on May 5 to 9pm on May 6, when elections are being held.
It comes after the union claimed RMT rep Gary Carney had been unfairly sacked.
In a letter written to all Central Line East Branch members in February, RMT general secretary, Mick Cash, labelled the “charges” against Mr Carney as “unfair, trumped up and completely unjustified.”
On Friday Mr Cash also said: “The sacking of Gary Carney is a blatant case of victimisation for trade union activities and his colleagues have made it clear that they stand shoulder to shoulder with him in this fight for justice.
“RMT will have no hesitation in escalating this dispute if LU don’t right this wrong.”
There may be some disruption to customers but we will do all we can to run a regular service on the Central Line during this action
Nick Dent, director of customer operations for London Underground said: “We are absolutely committed to ensuring that the Tube is as safe as possible for staff and customers at all times, something that is especially important as more customers return to the network following the easing of coronavirus restrictions.
“We have strict, long-standing drug and alcohol testing policies that have been agreed by all of our trade unions and will always take a zero-tolerance stance as part of our commitment to safety.
“We are disappointed by the RMT’s decision to announce this strike action. We urge them to call it off, and we remain open for further discussions.
“There may be some disruption to customers but we will do all we can to run a regular service on the Central Line during this action, should it go ahead.
“We will ensure that full travel information is available prior to the action so that customers can plan their journeys.”
The union said its member was not avoiding a drug and alcohol test.