Former attorney-general Michael Thomas has backed the government's blue bill on national security legislation, dismissing remaining concerns as matters of refinement. Referring to fears about proposed closed-door court hearings for groups banned on national security grounds, Mr Thomas said such measures were necessary and common. Local legal experts last week attacked the proposals to allow appeals by groups banned by the security chief to be taken to court in the absence of the groups' leaders and their legal representatives. But Mr Thomas, who is in Hong Kong representing the Department of Justice in a court case, said there were plenty of precedents for matters touching on national security to be considered in private because evidence was highly confidential and sensitive. 'If, for example, an undercover agent has penetrated a terrorist organisation that was planning to use explosives to undermine the government, evidence presented in open court would reveal the identity of the agent and put him or her at risk,' he said. 'The safeguard here is that a judicial officer has to consider this kind of evidence and, if it is insufficient, he can throw out the secretary for security's decision,' he said. Mr Thomas said the judge could also appoint an independent lawyer to act in the interests of the appellant and question the evidence. While Mr Thomas, who was attorney-general from 1983 to 1988, said that even though he had not read the blue bill on the laws based on Article 23 of the Basic Law as closely as local experts, he felt that it had broadly managed to balance national security with human rights considerations. The ultimate safeguards against any misuse of the law would lie with the judicial system and the binding international civil and human rights treaties that were a part of the Basic Law, he said. 'If a crank says 'kill Jiang Zemin', he has to satisfy the police that he really poses a serious threat, satisfy the prosecutors that he is worth prosecuting and you have got to have a conviction in front of a jury. 'These are all built-in safeguards,' he said. 'If a prosecution is launched malevolently, the courts will chuck it out.' Mr Thomas said it was unnecessary for a white bill, enabling further consultation, to be published and calls for a further draft did not seem to respect the integrity of the Legislative Council to do its job. He said it seemed that legal experts had made political points as well as legal ones in their submissions on the issue and the debate had become politically charged. He said the political consciousness of Hong Kong people had increased considerably since the days when he was attorney-general and people had come to realise the political reality that the special administrative region was obliged to legislate on national security. 'The bill has expressly confirmed people's right to criticise legitimately,' he said. 'It was a good thing to consult, and the government has plainly listened to the views expressed.' Mr Thomas also praised the development of the Court of Final Appeal in Hong Kong.