The Court of Final Appeal should not strike down restrictions on public demonstrations under the Public Order Ordinance unless their wording is found to be 'hopelessly vague', lawyers for the government told the court yesterday. Gerard McCoy SC said no other court in the world had been asked to define or rule on whether the term 'ordre public', as enshrined in Hong Kong law, was too vague. Hong Kong's highest court would be the first to do so, he said. The term is cited as one of the permissible reasons for restricting the right to demonstrate in Hong Kong, under the Public Order Ordinance. It was on 'ordre public' grounds that veteran activist Leung Kwok-hung and two others were convicted of holding an unauthorised assembly. They are appealing against the convictions, and have argued that the 'ordre public' restriction is too vague and open to abuse. Mr McCoy cited a case from Mauritius that said legislation which was 'hopelessly vague' had to be struck down as unconstitutional. Mr Justice Roberto Ribeiro, however, said the test the ordinance ought to be put to was whether the discretion given to the Commissioner of Police was 'capable of arbitrarily being exercised'. 'It seems that is the test rather than the 'hopelessly vague test',' he said. Mr McCoy said there were enough safeguards to prevent the police from abusing the term 'ordre public', despite the broad scope of its meaning. 'The commissioner cannot simply impose restrictions on a demonstration and state that it is because of 'ordre public' - that would be absolute nonsense,' Mr McCoy said. 'He has to give reasons ... has to state what has actuated him, with precision and reason.' Mr McCoy said the term 'ordre public' featured in a number of ordinances in Hong Kong, including the Mutual Legal Assistance in Criminal Matters Order with the US. Article 3 of that law states that Hong Kong may refuse assistance if 'the request for assistance impairs the sovereignty, security, or public order [ordre public] of the United States of America or, in the case of Hong Kong, the sovereign government responsible for the foreign affairs relating to Hong Kong.' 'Hong Kong's legislation even talks about the ordre public of greater China, not just Hong Kong,' Mr McCoy told the judges. The case continues on Tuesday before the five Court of Final Appeal judges.