Rights for millions of people who care for elderly of disabled relatives could be strengthened later by a ruling at the European Court of Justice.
A woman who said she was forced to leave her job because of her disabled son has won the latest round in her discrimination case.
Sharon Coleman, who resigned from her job as a legal secretary, is seeking a legal opinion in Europe after claiming she was forced to leave her job.
A European Court of Justice judge agreed that Sharon Coleman suffered "discrimination by association".
She claimed her former London employers described her as "lazy" for trying to take time off to care for her child.
She claimed her former London employers Attridge Law described her as "lazy" for wanting time off to care for her son.
Campaigners say the case may help provide protection for other carers.
Campaigners have said the case may help provide protection for other carers.
Ms Coleman said the law firm she worked for, Attridge Law, refused to allow her to work from home or work flexible shifts to care for her son, who has hearing problems.
She claimed her manager had commented that her child was always sick, and accused her of trying to use his condition to get out of work.
This case has profound implications Imelda Redmond Carers UK chief executive
When it was first announced in 2006 that her case would be heard by the European Court, Ms Coleman said she was overjoyed.
Since the UK instituted the Human Rights Act, few cases have been referred to Europe.
However, in this case the EU's Equal Treatment Directive's interpretation of disability discrimination is much wider than the UK's - in Europe, the person does not have to suffer from the disability themselves but could be the parent or spouse of a disabled person.
Carers UK chief executive, Imelda Redmond, said: "This case has profound implications for the one in five carers who give up work to care and face discrimination at work as a direct consequence of caring."
But Stephen Alambritis, from the Federation of Small Businesses, said some firms would find it hard to allow staff time off.
"The bottom line is profit, it's the viability of the business, making sure all staff are happy, including those with caring duties and those without.
"But in a workplace with four employees as it were, if one asks for time off that's a quarter of that work force out of the workplace and that can be difficult for a small employer.
