A union is taking a legal case on behalf of home care workers, saying they are paid less than half the minimum wage.
Seventeen home care workers employed across the London Borough of Haringey, backed by their union Unison, are taking a number of care companies and the council to court claiming widespread non-payment of the minimum wage.
The group, all but one of whom are women, are employed on controversial zero-hours contracts and care for elderly and disabled residents across the borough.
The women visit people in their own homes and in some cases provide 24-hour live-in care.
The case against care companies who took over a contract from Sevacare, centres on unpaid time spent travelling between people's houses.
Unison said on a typical day the women might be working away from home for 14 hours, but could receive payment for only half of them, leaving them earning as little as £3.85 an hour.
Care workers who provide live-in care can earn even less, getting as little as £3.27 an hour, well under half the legal minimum, said Unison.
General secretary Dave Prentis said: "Without the dedication of these committed and caring women, and thousands of others like them across the UK, our care system would collapse.
"The Government, local councils and the care companies all know that social care is in a dire state, that there's not enough money to pay for the care that's needed, and with everyone living longer the situation is going to get worse.
"The blame for the social care crisis must be laid at the Government's door. Ministers must get tougher with enforcing the law so firms aren't able to cheat their staff.
"More money must be put into care so that councils are not forced to tender contracts at a price they know decent care cannot be delivered. No wonder 15-minute care visits are now the norm, and there's widespread payment of illegal wages.
"Those paying the price for the Government's penny-pinching approach are the homecare workers - struggling to make ends meet on pitiful wages - and the people they care for. Their often complex medical needs simply cannot be catered for within the short time allocated by the care companies. Meanwhile the companies are coining it in."
Unison said it was biggest the union has ever taken involving home care workers.