All London Tube ticket offices to close, union claims
All 268 Tube ticket offices could be closed under "secret" London Underground plans, the TSSA transport union and Labour Party have warned.
They claim to have seen leaked documents that suggest the ticket offices will close and 6,000 jobs could be axed by 2020.
London Underground (LU) said 6,000 job losses was "completely unfeasible".
It said it planned to run more trains in future and continue to staff all its stations.
A leaked document seen by BBC London appears to show that closing ticket offices is an option being considered by Transport for London (TfL).
It lists every Tube station in the capital and under the heading that asks if a ticket office is staying open, it states "no".
The Transport Salaried Staffs Association (TSSA) said up to 6,000 rail and Tube jobs could be axed over the next six years.
The first 2,000 could go in the next two years with Tube ticket offices replaced by travel centres, mainly at major stations such as Waterloo and Euston, the union said.
TSSA general secretary Manuel Cortes said: "The mass ticket offices closures are just the start. We expect 6,000 jobs to be axed by 2020.
"We have a deal with TfL which clearly rules out compulsory redundancies. If Mayor Boris Johnson tears that up, all bets are off.
"Here is a man who was elected in 2008 on a promise to keep every ticket office open."
Shadow London Minister Sadiq Khan said: "Boris Johnson pledged to keep a ticket office open at every Tube station, in his manifesto.
"These revelations are a complete betrayal of that promise."
The managing director of LU and London Rail, Mike Brown, said: "We are investing in London Underground to support jobs and growth in London and across the UK.
"We are committed to running more trains and that all Tube stations will continue to be staffed in future, with staff visible and available to help our customers."
A statement from City Hall said the mayor had made the Tube "safer" and "more reliable".