23 passengers, including a child, were trapped in a lift at Elephant and Castle station for nearly an hour-and-a-half on Friday night whilst London Underground managers were in charge during a strike by tube staff.
The RMT union says that passengers' ordeal, which began at around 9.30pm, was prolonged unnecessarily because "inexperienced and inadequately trained" managers had been left in charge during strike action by the station's regular staff.
Staff at Elephant & Castle Underground Station, as well as at Charing Cross and Lambeth North, were on strike for the second time in less than a month to demand the reinstatement of colleague Jerome Bowes, who was sacked after an incident on New Year's Eve.
"This incident underlines why we believe it is irresponsible to leave scab managers in charge of any Tube station, not least a busy one with lifts," says RMT general secretary Bob Crow.
"We understand that managers left floundering by the emergency delayed calling the fire brigade, and that the fire service eventually responded to a call from one of the trapped passengers."
A Transport for London spokesman confirmed that the fire brigade had been summoned by a member of the public, but insisted that the industrial action "had no bearing" on how staff responded to the lift problem and all normal procedures had been followed.
Mr Crow added: "Under normal circumstances if it took more than 20 minutes to get people out, managers would be demanding to know why it had taken so long, and if it took more than an hour they would be looking for someone to discipline.
"Safety reps tell me that the failsafe systems on the lifts at Elephant and Castle are unusual, but the people normally staffing the station are familiar with them.
"Instead of parachuting in scab managers without the training, local experience and knowledge to cope when things go wrong, LUL should be sorting out the injustice to Jerome Bowes that has led to this dispute in the first place.
"RMT has now agreed to ballot Bakerloo line drivers at Elephant and Castle, and if LUL does not want this dispute to escalate that is what they should now do."
The strike action meant that Elephant & Castle station was closed during Friday's morning rush hour.