Free NHS home care for 280,000 people with chronic and debilitating conditions is guaranteed in the Personal Care at Home Bill now going through Parliament.
Health minister Andy Burnham has pledged a £670m-a-year funding package, which he says will also enable a further 130,000 to remain independent by providing equipment and services in the home.
Critics of the scheme, which was announced in the Queen's speech this month, claim that because the number of people who would seek free care has been underestimated, the cost of the Bill's provisions will be substantially higher.
Mr Burnham said: "This Bill is the first significant step towards making our system of care simpler, fairer and more affordable.
"It offers help now to the most vulnerable members of our society, most of whom have already paid out significant sums towards the costs of their care.
"People want to stay independent by living in their own homes for as long as possible. But we all face the prospect that one day we may need help with everyday tasks like washing and dressing.
"This shouldn't mean that an individual needs to move into residential care. Offering free personal care at home for those with the highest needs regardless of their means will help achieve this."
The Bill is also intended protect the savings of the 166,000 people who currently get free care and provide £130m to help people live at home for longer.