A suspended police officer seeking approval to set up a trade union has sent an ultimatum to the police commissioner. Senior Inspector Lau Kwok-fai has warned he will go ahead with his plan if he does not get an 'unequivocal reply' from force management by May 21. Mr Lau, who has been suspended pending disciplinary action over two convictions, sent a letter to Police Commissioner Tsang Yam-pui on Thursday after he said he had failed to receive a clear reply to his application in January to form a trade union. Mr Lau was fined $9,000 and had his driving licence suspended for 16 months following a conviction for a traffic offence in May, 2001. He was fined $3,000 five months later for indecent assault. Although force rules prohibit officers from joining a trade union, Mr Lau said the Basic Law guaranteed that right for residents. He said a police union would better reflect officers' views and protect them against some of the force rules, which he described as 'draconian' and unconstitutional. Mr Lau cited the example of a new police rule that bars him from defending colleagues in internal disciplinary hearings, saying he would seek a judicial review of the change as he had previously been allowed to act as defence representative even after he was suspended. The chairman of the Local Inspectors' Association, Tony Liu Kit-ming, said it was time the force clarified the rules on forming a trade union as the ban was introduced under colonial rule. 'Many people also have a misconception that having a trade union means having strikes,' he said. 'We can consider following the practice in the United States where police unions are allowed but officers are barred from going on strike.' The chairman of the Junior Police Officers' Association, Lau Kam-wah, agreed that police officers should have the right to form a union but he thought it might not be the time to do so. The rank-conscious culture of the force could leave the trade union with many operational problems. A force spokeswoman said it was studying legal advice about the request and would inform Mr Lau when a decision had been made. She said force rules prohibited suspended officers from performing any duties, including acting as a defence representative in internal disciplinary hearings.