Carers are to be allowed the right to request flexible working under new legislation.
Those defined as carers under the new legislation to come into effect in April 2007 will include employees who expect to be or who are caring for their partners, civil partners or spouse.
Also covered by the definition are adults looking after an adult who is a near relative or falls into neither category but lives at the same address as the carer.
The new step is part of a package of family-friendly measures introduced as part of the Work and Families Act 2006.
Employment relations minister Jim Fitzpatrick said that the government had consulted business, unions and carer's groups when coming up with the definition.
He said: "The government understands how difficult it can be for people to balance their work with caring for someone who is sick or disabled.
"We want to make sure that as many carers as possible have the right to request flexible working while at the same time not placing an unnecessary burden on business."