LAWS that failed to secure Chinese approval in the Joint Liaison Group (JLG) might be repealed after the 1997 change of sovereignty, the Attorney-General, Jeremy Mathews, told the Legislative Council. He was responding to a question by independent legislator Emily Lau Wai-hing on the progress of localising laws, echoing Governor Chris Patten's earlier warning of a possible ''legal vacuum''. Asked what would happen if the localisation process could not be completed before 1997, Mr Mathews said: ''There will be a high risk of those laws being declared by the National People's Congress as being incompatible with the Basic Law and therefore being repealed.'' He said approval of localised law depended on the JLG, but the Government had continued with its work. The British side had consistently reminded the Chinese side of the need to speed up progress to ensure continuation of the legal system in Hong Kong, he said. ''It will be in everybody's interests that these complex and technical subjects - technical, not political subjects - should be tackled on both sides with real commitment to see the job completed before July 1, 1997.'' Mr Mathews said speeding up progress and continuing constructive dialogue within the JLG was vital to the law amendment process. ''There is no reason why this work should not be completed on time,'' he said. He said most of the 600 ordinances in the statute book of Hong Kong had to be amended to comply with the Basic Law. The localisation and adaptation unit of the Legal Department had finished identifying laws which contradicted the Basic Law and a few papers had been passed to the Chinese side. But none of them could be tabled in the Legislative Council because they were awaiting approval from China. Asked how many legislative drafts had been put to the JLG, Mr Mathews would only say there were a few. The Legal Department chief rejected a suggestion that the Government had acted too slowly in localising laws. Responding to challenges from pro-China legislator Tam Yiu-chung, Mr Mathews said the department had acted quickly after the Basic Law was promulgated in 1990 to set up a localisation and adaptation unit, but could only start localisation after promulgation of the Basic Law. The last stage was to table the amended ordinances in the Legislative Council. None had reached that stage. Mr Mathews said the department wanted to increase manpower to speed up the work. He agreed with the Legco legal representative, Simon Ip Sik-on, that some of the amendments required only alterations of terminology, such as the replacement of the word ''Crown''. But he noted that there were important issues which needed to be resolved quickly, such as the Crown Land Ordinance and issues related to nationality.