Wang made the remarks Wednesday writing in a Chinese-language newspaper, implying that should Donald Tsang become the next chief executive on July 10, he will not be able to serve for longer than seven years.

Democratic Party member Yeung Sum said he believed Wang's latest explanation had a political motive.

Yeung said the pro-Beijing camp was angered by the suggestion that Tsang could be in place for 12 years, and consequently Wang was now attempting to correct the mistake.

``I really do not know when Wang is the guardian of the Basic Law and when he is not,'' he said.

He said Wang was challenging the core value of the Hong Kong people and the rule of law.

Wang, the law school vice-dean at Tsing Hua University, is seen as an authority on Beijing's thinking on the Basic Law.

He said there are two meanings to Article 46 of the Basic Law.

The provision stipulates that the term of office of the chief executive shall be five years. He or she may serve for not more than two consecutive terms.

He said the first meaning is that the term of office as a government position shall be five years but the chief executive's position could be held by two persons consecutively whose combined terms of office shall not be more than five years.

The second is that a person cannot take up the post more than twice, which is equivalent to a maximum of 10 years.

Wang's comment contradicts his explanation March 11 that Tung's successor might be able to stand for two more full terms.

In his earlier statement, Wang said that under international practice, should a successor's presidency not exceed half the full term, it will not be counted as one term of office.

Based on this, he said, Tung's successor could be re-elected twice and serve for a total of 12 years.

Secretary for Justice Elsie Leung has also said the chief executive chosen on July 10 can serve up to 12 years while constitutional affairs chief Stephen Lam said Leung was citing mainland practices when he made his earlier comment.

National People's Congress Standing Committee member Tsang Hin-chi said the committee will discuss whether Tung's successor could be re-elected twice when it meets again next month.

Chinese People's Political Consultative Conference member Chan Wing-kee said it is more appropriate for the SAR government to approach the NPCSC should the Basic Law need to be interpreted.

Chan said Tung's successor could be re-elected twice if his remaining term does not exceed half the full term of office.

Article 45 Concern Group lawmaker Audrey Eu said the Basic Law should be amended to clear up the dispute surrounding the term of the chief executive.

``Wang had earlier said the next chief executive could serve for 12 years. Now he is saying that as a position, the term of office shall be five years, and as an individual the person cannot take up office more than twice. It is different,'' she said.

Eu said her group will meet with Leung to discuss the interpretation of Basic Law and the terms of office for the chief executive.

Chinese University political scientist Timothy Wong said the the dispute needs to be settled either through interpreting or amending the Basic Law.

``We cannot rely on the opinions of the legal experts. This does not contribute to a discussion on the issue,'' he said. teddy.ng@singtaonewscorp.com