Businesses should, as far as is reasonable, make adjustments to support employees who are caring for disabled family members, the Equality and Humans Rights Commission (EHRC) will tell the Court of Appeal today.
The EHRC will make its statement in a case involving the Ministry of Defence (MOD) and Dr Christine Hainsworth who worked for the MOD.
Dr Hainsworth had requested a transfer to the UK to enable her disabled daughter's special educational needs to be met, but her request was refused and she claimed unlawful disability discrimination.
Her claim was previously rejected by the Employment Tribunal and the Employment Appeals Tribunal.
The case will see the Commission intervene as a third party to assist the court with equality and human rights advice.
It will warn that a failure by an employer to make reasonable adjustments may well have a knock on effect on a carer's ability to continue work and on a disabled person's ability to train, find or retain work.
Commission chief legal officer Rebecca Hilsenrath said: "Equality and human rights legislation is here to protect everyone and the duty to make reasonable adjustments should benefit everyone.
"There are three million employees in England and Wales who provide huge value and a vital service to the country as unpaid carers. Many of them look after disabled family members.
"Carers also provide value to their employers and research suggests that a flexible approach to supporting employees with family responsibilities increases productivity and enhances employee commitment. In this way, carers achieve a decent work-life balance and employers continue to derive the economic benefit of motivated, experienced staff," she added.
In its case, the Commission will ask the court to consider whether EU legislation obliges an employer to make reasonable adjustments where they are required to accommodate the needs of a disabled person who is cared for by the worker and, if so, whether EU directives can be read into the Equality Act 2010.
The Commission also believes that the United Nations Convention on the Rights of Persons with Disabilities strongly supports Dr Hainsworth's case and will argue that European law should be interpreted in light of the Convention.