Union leaders have warned of huge cuts on London Underground as a result of the Government's clampdown on spending, saying that a row over 800 ticket office job losses could be the "tip of the iceberg".
The Transport Salaried Staffs Association (TSSA) spoke out after obtaining a memo to staff from Transport Commissioner Peter Hendy warning of the "very significant effects" of the Government's spending review.
Mr Hendy said the Treasury had asked all non-protected Government departments to set out what budget cuts of 25% and 40% up to 2014/15 would mean for their spending.
"All departments affected, including the Department for Transport which provides some £3 billion a year of our funding, have now submitted their projected cuts to the Treasury based on these scenarios. Discussions between departments and the Treasury will continue over the summer, before the Chancellor makes his announcement on 20 October about where the cuts will actually fall.
"Notwithstanding the work we have been undertaking to mitigate the impact, we are faced with having to sustain a considerable reduction in our funding," said the memo.
Mr Hendy warned that London was the engine room of the UK economy and ill thought-out cuts would "seriously impede" the country's economic recovery.
TSSA general secretary Gerry Doherty said: "If TfL lose anything like £1 billion from its budget, the ticket office cuts will just be the tip of the iceberg. We could be looking at two or three times that amount because TfL have already halted all capital spending."
The TSSA and the Rail Maritime and Transport union are balloting their members on industrial action over the ticket office job losses and Mr Doherty warned that strike ballots would be called to halt any new threat to jobs in the autumn.
TfL announced on Wednesday that a multimillion-pound contract to redevelop Bond Street Tube station will be awarded to Costain Laing O'Rourke, with the main construction work getting under way next year.
Read More
When completed in 2017, the £300 million redevelopment will increase capacity ahead of the completion of the Crossrail project and reduce congestion at the station, which is used by 155,000 passengers a day.
