Two elderly UK sisters have lost their bid to challenge inheritance tax laws at the European court of human rights.

Joyce and Sybil Burden, aged 90 and 82, were trying to get the same treatment under inheritance tax laws as married couples and couples in civil partnerships.

The pair have lived together all their lives and fear one sister would have to sell their four-bedroom home in Marlborough the other died.

However, the ECHR judged that without a legally-binding agreement the Burdens relationship of co-habitation was “fundamentally different” to that of a married or civil partnership couple and the chamber of 17 judges voted 15 to two against the sisters.

The court stated: “The Grand Chamber agreed… given the applicants’ age, the wills they had made and the value of the property each owned, they had established that there was a real risk that, in the not too distant future, one of them would be required to pay substantial inheritance tax on the property inherited from her sister.

“In those circumstances, they could claim to be victims of the alleged discriminatory treatment.”

However, it found: “The absence of such a legally-binding agreement between the applicants rendered their relationship of co-habitation, despite its long duration, fundamentally different to that of a married or civil partnership couple.

“The Grand Chamber concluded that the applicants, as co-habiting sisters, could not be compared… to a married or Civil Partnership Act couple.”

Under current inheritance tax rules, people face death duties of 40 per cent on assets over £300,000.

However, married couples and those in civil partnerships avoid the charge when assets are moved within the partnership.

In 2006, after losing their first case, Joyce Burden told the BBC: “If we were lesbians we would have all the rights in the world.

“But we are sisters, and it seems we have no rights at all.”

Their home is reported to be worth £875,000 – meaning in the event of one sister’s death the remain Ms Burden would face a bill of £230,000.