The head of the Central Policy Unit yesterday played down the controversial appointment of former Democrat and commentator Lau Sai-leung to the think-tank. Although criticised as anti-leftist by a pro-Beijing Executive Council member, Mr Lau was only one of many brains serving the CPU, said its chief, Lau Siu-kai, who is a professor on secondment from Chinese University. Mr Lau, appointed to the think-tank full-time last week, was criticised for his lack of policy research experience that has aroused concerns, as most of his predecessors were prominent academics with solid research backgrounds. But Professor Lau said: 'We never said our members should [be] confined to certain expertise.' He said there were other senior researchers and part-time members. 'Our policy research network far exceeds 100 people,' he said. Professor Lau declined to respond to criticism of Mr Lau's political stance. 'I'm not going to comment on that. Things will get complicated if I dwell on this.' Asked if the appointment was Chief Executive Donald Tsang Yam-kuen's choice alone, Professor Lau said, 'We both made the choice.' Mr Lau said yesterday he was pleased with the job and would discharge his duties with professionalism. He said he had already been following some policy research. Mr Lau has been criticised by Exco member Tsang Yok-sing for his critical stance towards the pro-Beijing camp.