The central government is determined to find a way to interpret the Basic Law to allow the next chief executive - widely tipped to be Chief Secretary for Administration Donald Tsang - to serve only the remainder of Tung's current term, until 2007.

Beijing has opted for the controversial solution because the Chinese Communist Party's Politburo wants Tung's successor to serve two years in office instead of giving him a five-year mandate, a key adviser to Beijing said.

Beijing rulers prefer an interpretation of the Basic Law because they don't want to upset other candidates with ambitions of being the next chief executive. They also don't want to cause friction in the business sector, the source added.

Some legal scholars have said in the wake of the resignation news, that the Basic Law clearly says the successor should serve a full five-year term.

Tung, who decided to quit after years of turmoil, was greeted by hordes of reporters when he arrived at his Beijing hotel.

When asked about his expected departure, Tung neither confirmed nor denied his resignation, which has been accepted by the party's Politburo.

``I know that there are so many questions that you all want to ask. I will explain them clearly in an appropriate time,'' he said.

The National People's Congress Standing Committee will hold a special meeting to consider the length of a successor's term, not unlike the procedure followed in April last year when Beijing ruled out universal suffrage for Hong Kong in 2007-2008. It is expected to rule that Tung's successor will serve until June 30, 2007, after the NPC's plenary annual meeting ends on March 14.

The next chief executive will be elected by the current 800-member Election Committee before July 13, the day the committee is dissolved.

The move is set to provoke another round of controversy over the validity of the one country, two systems concept and the rule of law in Hong Kong as this will be the second Basic Law interpretation within a year and underscores Beijing's strict political control of the territory.

Already, many local pro-Beijing politicians are unhappy with the central government's unilateral decision to handpick Tsang as Tung's successor because they have been excluded from power politics of being the ``kingmaker.''

Local NPC deputy Ng Hong-man said a new chief executive should serve for five years as stipulated by the Basic Law. ``The Basic Law doesn't say a chief executive replacement should serve the remaining term of office,'' he said. ``I reckon that if a new chief executive is to be elected, he will serve for five years until 2010,'' he said.

If this is the case, the political reform set out for the 2007's electoral system will be scrapped, and that, Ng argued, might explain why Tung chose to go when Hong Kong's economy is turning for the better.

``I think the tell-tale part about Tung's mysterious departure is that there will be no political reform in 2007. This will save a great deal of political wrangling in Hong Kong.''

The interpretation will center around Article 52 and 53 of Hong Kong's mini-constitution, the source said, which states that the chief executive must resign if he loses the ability to discharge his duties as a result of serious illness and a new leader shall be selected within six months. During the period of the vacancy, his duties shall be taken over by the Administrative Secretary, Financial Secretary or Secretary of Justice, in this order of precedence.

Since Article 46 of the Basic Law says the term of office of the chief executive shall be five years, the NPC Standing Committee will insist through the interpretation that the replacement for the incumbent chief executive should serve out his remaining term of office instead of a new five-year mandate.

This approach runs contrary to the opinion of many pro-Beijing politicians who want Tung's successor to serve a new term of five years to save the trouble of tinkering with the Basic Law.

Beijing has been left with no choice, the source insisted, and is forced to adopt this controversial approach to prevent a possible constitutional bombshell in the form of a legal challenge.

``If the new chief executive is to serve for five years, it means that the chief executive for the third term will have to be elected by the current Election Committee. This is set to trigger legal disputes and will easily be subjected to legal challenges in the form of a judicial review,'' the source said.

``If this administrative approach is challenged in court, it means that the Basic Law and one country, two systems would be on trial. That would be unprecedented and could provoke a constitutional crisis that would be too much for Beijing to bear,'' the adviser said.

The source said Beijing is wary of being dragged through the courts. Beijing also fears that pro-democracy politicians could pose a significant legal threat to the next chief executive if he is given a five-year term of office.

carrie.chan2@singtaonewscorp.com

cannix.yau@singtaonewscorp.com