Tube staff balloted over dismissal of London Bridge worker
London Underground station staff will be balloted for strikes in a row over the sacking of a Tube worker.
Members of the Rail, Maritime and Transport union based at London Bridge are due to strike on Sunday in protest at the dismissal of a colleague.
All RMT station workers will now vote on whether to launch action following union warnings it would spread the dispute across the network.
Tube bosses said the worker was sacked after a "thorough investigation".
RMT General Secretary Mick Cash said the worker and two colleagues, who were also disciplined, had been "subject to a vicious assault by a violent fare-evading passenger" at London Bridge.
"Instead of being supported and commended by the company, they have been wrongly punished," he said.
But Brian Woodhead, operations director for London Underground, said the events described by the union are "simply untrue".
"CCTV footage from a number of different angles clearly shows a staff member displaying unacceptable conduct when dealing with a member of the public," he said.
Sunday's 24-hour strike at London Bridge will begin at 22:00 BST.