The importance of building the rule of law has, for good reasons, featured prominently in Beijing's vision for China's future. Premier Wen Jiabao took up the theme this month in his report to the National People's ongress. 'We will conscientiously implement the basic policy of governing the country by law ... and speed up work to build a law-based government,' he said. Beijing has everything to gain from upholding the rule of law in the one part of China where it is long established. But the moves towards imposing a two-year term for the new chief executive have already damaged the rule of law in Hong Kong. Even greater harm will be done if the decision is pushed through. The Basic Law provides only for a five-year term. The benefits of sticking to the law outweigh any perceived advantages of departing from it. It is not too late to think again. Beijing appears to recognise that the decision will undermine the 'one country, two systems' concept. It is reluctant, and wisely so, to formally interpret the Basic Law in order to impose the two-year term. This, as the central government knows, would attract criticism both in Hong Kong and overseas. An interpretation, however, looks increasingly likely. Beijing may be cautious but the impetus seems to be coming from the Hong Kong government. Nothing could be more damaging to the 'one country, two systems' concept than Hong Kong being seen to connive at the erosion of the rule of law. These worrying consequences could easily be avoided. All the central government has to do is to adhere to the clear wording of the Basic Law - and trust the new chief executive with a five-year term. Survival of the common law lies at the heart of Hong Kong's post-handover arrangements. That system requires that the law means what it says (unless the wording is unclear). This is how the legislative intent of the Basic Law should be determined. Unambiguous Secretary for Justice Elsie Leung Oi-sie has admitted that the government had, until recently, believed the Basic Law to be 'clear and unambiguous' in providing only for a five-year term. There is no need to conjure up old drafting documents or construct elaborate arguments about the structure of the Basic Law. The law says five years - and that is what it should mean. There are two considerations which the central government would be wise to take into account before making the next move. The first concerns practical matters. It may well be that Beijing wants what acting Chief Executive Donald Tsang Yam-kuen represents. He offers stability through a strong civil service, the essence of Hong Kong's executive-led governance. But the central government does not appear to fully trust Mr Tsang - at least, not yet. He is a knight of the British realm who is strongly associated with the colonial past. So a solution might be to put him in charge for a trial period - the remainder of Tung Chee-hwa's term. He could then be replaced with a new leader in 2007 if things do not work out. This might seem a sensible move, but it has some serious drawbacks. What happens if Mr Tsang has to step down before 2007 for some reason? We could end up with two elections in the space of a few months. A shortened term would also make it very difficult for Mr Tsang to achieve either unity or stability. He would be presiding over a cabinet likely to include people who wish to topple him in 2007. Mainland legal experts have pointed to the practice overseas where a deputy can take over for the remainder of a leader's term. But in election-based systems this is usually only until the next election, as in the United States and United Kingdom. The winner then serves a new term of the usual length. This is just what the Basic Law provides for. Two evils The second, more important reason for allowing a five-year term is to protect the Basic Law. Hong Kong's constitution is of little use if we cannot be sure that it means what it says. Beijing has interpreted the Basic Law twice since the handover. Both interpretations provided a political response to unexpected events. A surprise court ruling against the government led to intervention in 1999. And the mass demonstration on July 1, 2003, appeared to prompt the restrictions imposed last year on political reform. The same will be true if the National People's Congress Standing Committee steps in to impose a two-year term; the unexpected event was Mr Tung's resignation. The immediate consequences of the interpretations may appear beneficial. This is because they are politically expedient. But the damage to the Basic Law is cumulative and long-lasting. How, in future, can we know when the words of our constitution will again become hostage to political developments? The central government's decision can be seen as a choice between two perceived evils. Either it trusts Mr Tsang with a full five-year term - or it allows serious damage to be done to the rule of law in Hong Kong. The scales are weighed heavily in favour of a five-year term. This solution is in the best interests of Hong Kong and China as a whole.