The Rail, Maritime and Transport Union (RMT) has announced it will ballot all Tube workers to protest the sacking of a colleague at London Bridge.
The RMT has intervened regarding the case of a worker at London Underground station who was dismissed following an incident with an alleged fare dodger.
London Underground claims CCTV footage shows the employee's "unacceptable conduct", while the union is claiming the ticket barrier worker intervened to stop an assualt on fellow workers, including one who was pregnant.
From Sunday at 10pm, all RMT members working at London Bridge station will engage in industrial action until 10pm on Monday.
This new ballot will propose strike action across the entire network to walk out against what the RMT sees as an unfair sacking.
A representative of Transport for London told the Evening Standard the organisation does not expect the entire network to vote in favour of a strike.