Passenger numbers on the London Underground have declined during the coronavirus outbreak, Transport for London (TfL) has said.
As of 2 March, the number of people using the Tube dropped by 19% compared to the same week in 2019. Data also showed a 10% drop in London bus riders.
It comes after a significant reduction in visitors to London and firms asking staff to work from home, TfL said.
TfL said it had forecast a reduction in passenger income of up to £500m.
The London Underground network carries 1.35 billion passengers every year, according to TfL, while about 2.1 billion bus journeys are taken in the capital.
TfL said its cash balance of over £2bn was well above the required minimum and would allow the initial impact of coronavirus to be managed but said it would need financial support from the government.
Simon Kilonback, TfL's chief finance officer, said: "We manage our finances prudently, and have reduced our deficit hugely in recent years. This means that we can manage the impacts on our passenger numbers and finances that are currently envisaged.
"But, given the nature of the situation, we will be looking to the government to provide appropriate financial support.
"We continue to follow and communicate Public Health England advice, including that there is no specific risk on public transport."
Train driver union ASLEF said it would work with TfL to help keep vital services operating.
"Our approach will be to do what is right, not just in the interests of our members, but of their families and of the wider communities we all are part of."