London: A rule stipulating that non-European Union spouses of British citizens should be at least 21 years of age before being allowed to come and stay in the UK was struck down by the Supreme Court on Wednesday.

The rule introduced by the former Labour Government in 2008 affected thousands of people, including British citizens with origins in the Indian sub-continent who seek matrimonial alliances in India, Pakistan, Bangladesh and Sri Lanka.

The ban on non-EU spouses below the age of 21 was brought to prevent forced marriages. The court decision is seen as a setback to the David Cameron government's aim to prevent and stop forced marriages.

The court said the rule was unjustified because it interfered with the human rights of couples and the right to a private family life under Article 8 of the European Convention of Human Rights.

Immigration Minister Damian Green said the judgement was "very disappointing" because the policy had been judged elsewhere in Europe to be lawful.

The case was brought by two couples, Briton Amber Aguilar and her husband, Diego, from Chile, and Briton Suhyal Mohammed and his Pakistan wife Shakira Bibi. In both cases, there was no evidence or suggestion that they were forced marriages.

Green said, "This is another very disappointing judgement, which overturns a policy that exists and is judged to be consistent with the ECHR in other European countries. The judges themselves agreed increasing the marriage visa age had a legitimate aim."

He added, "We believe this decision will put vulnerable people at risk of being forced into marriage. We will come forward with our response in due course."

The Joint Council for the Welfare of Immigrants (JCWI), which represented Amber and Diego, estimates the ruling could allow up to 5,000 foreign spouses to settle in the UK every year.

Habib Rahman of the JCWI said, "This was a law introduced on the hoof, which had no discernible effect on forced marriage, but infringed on the rights of UK citizens to live in the UK with their partners. We are delighted to see it consigned to the scrap heap of misguided legislation."