Appeal court judges are prepared to reconsider their ruling on the validity of the provisional legislature in a challenge to the Government launched by child migrants yesterday. Chief Judge of the High Court Patrick Chan Siu-oi said extra time may have to be set aside for new arguments on the legality of the interim body to be put before the court. He and two other judges considering the child migrants' appeal dismissed claims that the provisional legislature was unlawful in a landmark ruling last July. That judgment was in a different case and it had been thought the judges may refuse to reconsider the issue. But Denis Chang SC, for the children, was told to proceed as he saw fit. Chief Judge Chan said the court would be prepared to listen to the so-called 'PLC point', but it would hear other arguments in the case first. Five children are involved in test-case challenges to controversial new immigration legislation introduced soon after the handover. They claim the provisional legislature, which passed the laws, is not a valid body because it is not provided for in the Basic Law. The children's lawyers argue that the Basic Law gives them the immediate right of abode because they have parents who are permanent residents. Mr Chang told the court the migrants should not be forced to return to the mainland to comply with exit procedures which apply there. He attacked the judgment of Mr Justice Brian Keith, who had backed the Government's measures at the Court of First Instance. 'It is clear he was attracted to the arguments based on the SAR's high degree of autonomy. He pointed out the dire consequences of allowing that autonomy to be undermined.' But the judge had then interpreted the law in a way which 'had the effect of doing precisely that', said Mr Chang. The new legislation, introduced on July 10 last year, forces migrants seeking to exercise their right of abode to obtain a 'certificate of entitlement' and to attach it to a travel permit obtained on the mainland. Chief Judge Chan, Mr Justice Barry Mortimer and Mr Justice Gerald Nazareth, will continue to hear the case today.