Hong Kong chief executive is not above the executive, judicial and legislative powers - according to the Basic Law
John Chan says the power of HK's leader is today limited by the Basic Law, in contrast with colonial days
In April 1987, when China's paramount leader Deng Xiaoping met the Basic Law Drafting Committee members in Beijing, he criticised the suggestion to introduce the principle of separation of powers to the would-be Hong Kong Special Administrative Region. He said Hong Kong could not copy directly from the West.
The then undemocratic system in Hong Kong was based on the British system, and had been in practice for a century and a half. Deng said it would not be appropriate to introduce to such a system the separation of powers or a British or American parliamentary system, just so it could be seen as a democracy.
After Deng's comments, the drafting committee ceased using the term "separation of powers".
While Zhang may be correct from a strictly legal point of view, in reality, the political system in Hong Kong has evolved since the colonial era to put in place by convention - in practice and in spirit - the principle of separation of powers. The three branches of government each have their own role and function, creating checks and balances between the executive and the legislature, while upholding judicial independence. Whatever term one may use to describe it, it is separation of powers in a real sense.
Zhang described the chief executive as having a "dual head" status, that is, he is head of the Hong Kong government and at the same time head of the SAR. Zhang also said that the chief executive has "dual accountability", that is, he or she is accountable to the central government and also to the Hong Kong government.