A mainland-born teenager missed out on the right of abode because the Court of Final Appeal made a mistake in last week's ruling on the case of more than 5,000, a new legal challenge claims. Lawyers for Lau Pong, 18, took the rare step yesterday of lodging a request for a 'clarification' of the ruling with the top court in an attempt to win the right for him to stay in Hong Kong. They argue that the judges failed to take into account facts which make it clear Mr Lau, one of 25 representative applicants, qualifies for right of abode under general legal principles established by the court in the ruling. The lawyers are asking the judges to review the case in the light of these facts and to reverse their decision last Thursday not to allow the teenager's appeal. Robert Brook, from Pam Baker and Company, confirmed an application had been lodged. The court has laid down a timetable for parties to the proceedings to make written submissions on the issue. 'If there is any dispute, the court can order a hearing,' Mr Brook said. 'If the Director of Immigration consents to the application, there would not be any need for a hearing.' The court ruled that a government 'concession' allowing certain applicants the right of abode should be extended to those who made a claim for legal aid - as long as the Immigration director was notified before January 29, 1999. Mr Lau, whose father is a permanent resident, applied for legal aid on July 27, 1998, when 15. The Legal Aid Department provided evidence during the case that it had faxed and posted notification of the claim to the Director of Immigration on the same day. This would appear to put him within the concession. But when the court came to deal with Mr Lau's case, it said the Director of Immigration had not become aware of his application for legal aid until July 1999. Therefore, it 'did not amount to a claim lodged with or referred to the Director of Immigration within the concession period'. The court did not mention the evidence from the Legal Aid Department that Mr Lau's claim had been sent to the Director of Immigration in July 1998. Mr Lau's lawyers have suggested immigration officials lost the original fax and letter sent by the Legal Aid Department in 1998. This, they say, would explain why the Director of Immigration was not aware of his claim until the following year. In the application filed yesterday, Mr Lau's lawyers ask for a clarification of parts of the judgment referring to him. They request that his appeal be allowed, that the removal order made against him be quashed and that a declaration be made stating that he falls within the concession. If successful, the challenge would enable Mr Lau to join his family in Hong Kong. His father came here in 1982 and his mother has been a resident since 1997. The request for a clarification revives memories of the Government's controversial application in February 1999 for the court to clarify its landmark abode ruling of the previous month. The court agreed, on that occasion, to clarify that it had not intended to challenge the authority of the National People's Congress.