The European Commission of Human Rights has asked the Government for a written response by 25 July to a claim by Chris Morris that the 18-year age limit is discriminatory and breaches the right to respect for his private life.
This means that the Government will have to decide whether to contest the case, the latest in a series brought in the European courts over gay equality issues.
Successive Labour Party conferences have voted in favour of lowering the age of consent to 16 for homosexuals, and Jack Straw, now the Home Secretary, pledged in a pre-election speech last February to allow a free vote in the Commons.
It is not known when that vote will take place, but given the size of the Labour majority, it is most probable that the age of consent will be lowered. It is unlikely that the Government would want to defend in Strasbourg something which the Commons will decide is indefensible
Mr Morris, who was 16 when he lodged his application in Strasbourg, has been abused by fellow pupils for being gay and was on one occasion assaulted by a group of boys on a bus. His tormentors taunted him with the fact that he was breaking the law.
Mr Morris, of west London, turned 18 last week and is sitting A-levels next year. He said yesterday that he realised he was homosexual at 13 and had his first relationship two years later.
"I had a lot of hostile responses initially, and there was the added burden of knowing that what I was doing was illegal," he said. "I feel that by discriminating against us, the Government gives out a very clear message to everyone else that it is fine to bash gays."
Mr Morris is arguing that the 18-year age limit contravenes two articles in the European Convention on Human Rights. His case mirrors that of Euan Sutherland, a student whose challenge to the law on age of consent was declared admissible by the commission last year. The Sutherland claim was fiercely contested by the last Conservative government.
The commission, which screens cases for the European Court of Human Rights, is expected to issue a report shortly outlining its view of the merits of Mr Sutherland's claim.
Stonewall, the group that campaigns for homosexual rights, called on the Government yesterday to allow the free vote to take place as part of the Crime and Youth Justice Bill.
Angela Mason, Stonewall's director, said: "It is looking increasingly likely that the European Court of Human Rights will rule that the unequal age of consent is a breach of human rights. The Government is committed to compliance with the European Convention. They should make time for a debate and vote on this as soon as possible."
Given Mr Sutherland's success so far, the Government is unlikely to dispute the admissibility of Mr Morris's case. But it is likely to receive the same legal advice as the Tory government on the issues raised, and lawyers believe it may argue that there is no point in taking Mr Morris's claim further until the European Court has ruled on the Sutherland case.
A free vote in the Commons would almost certainly result in a majority in favour of reducing the age limit to 16. When the age of consent for homosexuals was brought down from 21 to 18 in 1994, a motion to lower it to 16 was defeated by only 27 votes.Reuse content