Union leaders claimed today that London Underground bosses were secretly drawing up plans to save £5 billion in spending which will see 144 station ticket offices close and up to 1,200 jobs threatened with the axe.
The Rail Maritime and Transport union said managers had been called to a "high level" meeting of senior staff today to discuss spending cuts.
Transport for London denied there were any plans to make an announcement about cuts.
Bob Crow, general secretary of the Rail, Maritime and Transport union, said: "The savage cuts to jobs and ticket offices exposed by RMT in the leaked document just before Christmas show that all the pledges about services to passengers being protected from the £5 billion cuts programme are worthless.
"London Mayor Boris Johnson, the chairman of Transport for London, was elected on an explicit manifesto pledge to ensure a manned ticket office at every station.
"RMT challenges the Mayor to stick by that pledge and demand the binning of this cuts plan or stand exposed as a hypocrite who rips up key manifesto commitments to the voters who put him into office.
"The job cuts being cooked up behind closed doors for Underground stations would leave passengers dangerously exposed in the event of an emergency and would ratchet up the dangers for the public, particularly women, travelling late at night.
"It is clear from the draft plans that LU bosses are pushing towards an under-staffed operation of stations regardless of the risks.
"RMT will mobilise a campaign to stop the cuts and this union will take whatever action is required to defend our members' jobs and a safe and efficient service for the travelling public."
A Transport for London spokesman said: "We are committed to staff on all of our stations throughout the day to provide the best possible service for our customers.
"As we invest billions to upgrade the network, we will be running more frequent and reliable Tube services for Londoners and commuters.
"As we've said before, given the current economic climate and the need to be ready for the changes that will arise when the Tube upgrades are delivered, we are looking at how we can be best organised to provide that service. This work is ongoing and no decisions have been made."