Transport for London is trying to save £16m a year
A lobby group representing London's top businesses has taken to the streets to protect investment in London transport.
Members of London First demonstrated outside Westminster Tube station during the rush hour to ask commuters which party they trust to protect journeys.
The group called on the three main parties to avoid "easy" spending cuts to Crossrail and key Tube improvements.
London First head Baroness Valentine warned that cuts would create "cattle-class misery" for Tube passengers.
About 40 people from London First had been outside the station opposite Parliament on Wednesday morning, wearing masks of Prime Minister Gordon Brown, Conservative leader David Cameron and Liberal Democrat leader Nick Clegg.
They carried boxes marked with each party's name and asked commuters to cast their vote for the party they believed will safeguard London transport.
Earlier this year, London Underground announced cuts to 800 jobs among managers and ticket offices in a bid to save £16m a year in the wake of the recession.
London First Chief Executive Baroness Valentine acknowledged "huge pressures" on public spending, but she insisted: "If London is to remain a global talent hub and a centre for world trade, we must not sentence millions of commuters to the cattle-class misery of an overcrowded Tube.
"The Tube matters to business and it matters to London - it is the capital's lifeblood."
She also called for cross-party support for Crossrail, which will link towns to the east and west of the city with Heathrow, the West End and Canary Wharf.
Tessa Jowell, Labour's Minister for London said: "All Londoners know we need more capacity in our transport infrastructure, that's why the central issue today is Crossrail, and only Labour is fully committed to delivering it.
"The Conservatives have said they cannot guarantee Crossrail will go ahead and the Liberal Democrats' London manifesto did not even mention it."
Teresa Villiers, Conservative spokesman for transport, said: "We support Crossrail which is an important piece of infrastructure for the capital and we would reform the way our railways are run to improve conditions for commuters and address overcrowding."
The Liberal Democrats' spokesperson for London, Tom Brake, said: "For London to maintain its pre-eminent position, its transport infrastructure needs both a well-funded maintenance regime and new lines like Crossrail.
"Without it, London will ground to a halt."