The European Court of Justice has ruled that the mother of a disabled son barred from working flexibly by her former employer, does have the right to sue for discrimination.

The Luxembourg court came to a unanimous agreement that Sharon Coleman has the right to make a claim for "discrimination by association", after she argued that she was forced out of her job as a legal secretary after being branded as lazy and blocked from progressing her career as a result of needing to take time off to look after her son.

Rather than claiming for "special" treatment for the disability, Ms Coleman has argued that discrimination laws apply not only to the disabled but also to those responsible for looking after them, with the court's advocate general Poiares Maduro agreeing, explaining that "one way of undermining the dignity and autonomy of people … is to target not them, but third persons who are closely associated with them".

Speaking after the ruling, Ms Coleman stated: "This has been a long, hard battle and it is not over yet, but I am thrilled that the European court has ruled in my favour. This decision will mean so much to so many people."

According to the Equality and Human Rights Commission, which supported the case, the ruling could affect many of the estimated six million Britons who act as voluntary carers, bringing them under the protection of the Disability Discrimination Act.