Commuters swarmed into Underground stations on Tuesday, where the sharply reduced service meant that trains were as packed as on an ordinary workday, and the government showed no inclination to reduce those numbers. Instead, it urged Transport for London, which is run by the city’s mayor, Sadiq Khan, to restore normal service.

“In work, in many, many instances, the two-meter rule can be observed,” said Britain’s health secretary, Matt Hancock, referring to the social distancing that the government is promoting. Those who cannot work from home should go to work, he said, “to keep the country running.”

Part of the problem, analysts said, is that the government has not yet rolled out fiscal measures to cushion the blow to self-employed workers who lose their jobs. Britain’s chancellor of the Exchequer, Rishi Sunak, said that the Treasury was scrambling to put together a package, but that it was “incredibly complicated.”

Britain’s determination to keep parts of the economy operating, even as it tries to isolate much of society, carried echoes of the debate in Washington, where President Trump has argued that shutting down the economy for several months could be more damaging than the epidemic itself.