Tube cleaners employed by contractors Initial and ISS continued their strike for better pay today.
The RMT members walked on at 5.30am on Monday for 48 hours.
"It is time for London Mayor Boris Johnson to stop talking about a living wage and start acting to make sure that contractors on his services actually deliver it," RMT general secretary Bob Crow said.
"It is these same staff who have played a key role in keeping services clean and safe who are now forced again by their employers to take action for a living wage and recognition of their efforts."
An ISS spokesman claimed: "We will continue to provide a safe environment for passengers and Tube workers alike."
Official inflation figures understate the real extent of rising costs, but even the government's own CPI scheme lays bare the ongoing misery for working people and those dependent on benefits.