A top mainland legal expert has changed his mind again about the maximum number of years the next chief executive can serve. Speaking at a Basic Law symposium, Wang Zhenmin , senior research fellow at the Institute of Hong Kong and Macau Affairs, said Tung Chee-hwa's successor should be entitled to run for two full five-year terms, in addition to serving the remainder of Mr Tung's term. He said he had never changed his position on the maximum term a chief executive could serve. 'Unlike others who perhaps have changed, I have never changed,' Professor Wang said. However, in an article for the Chinese-language Ming Pao newspaper, he wrote that Article 46 of the Basic Law said no individual could serve as chief executive more than twice - meaning whoever wins in July could serve seven years at most in the job. Yesterday he reverted to his original stance, saying that if the remainder of an outgoing chief executive's term was less than half the full term, or 21/2 years, then it would not be considered a full term. The new chief could then technically be re-elected twice. Based on that claim, if acting Chief Executive Donald Tsang Yam-kuen was elected in July he could serve up to 12 years, five months and 29 days. Legislator Emily Lau Wai-hing, who was booed by the symposium audience, said Professor Wang's shifting stance raised doubts about the credibility of mainland experts' views on the matter. 'It clearly shows they have little idea of the rule of law. They could say whatever they want without any backing,' she said. Legislator Ronny Tong Ka-wah, from the Article 45 Concern Group, said Professor Wang's remarks should be publicly debated to see whether they could be accepted. The latest twist in the saga over the next chief's term of office came as officials again defended the government's move to seek an interpretation of the Basic Law from the National People's Congress Standing Committee. Gao Siren , director of the central government's liaison office, said interpreting the Basic Law could 'relieve doubts and end dispute' over issues related to the new chief executive's term. Mr Tsang, the frontrunner, called on the public to be open-minded about the need for the interpretation, saying it was in the best interests of the community.