On Saturday, Chief Executive Donald Tsang Yam-kuen maintained that the Basic Law did not impose any nationality requirement on deputy ministers.

After initially refusing to disclose the salaries of the deputy ministers and political assistants, citing their right to privacy, the government on Saturday made public the salaries being paid, but not who earns what. The salaries were decided by Mr Tsang on the advice of an appointments committee.

However, Mr Wong said: 'What is lawful may not be right politically. Politics is politics. It's never a privacy or a legal issue.'

In an interview with the South China Morning Post, he was adamant that the appointees' salaries must be disclosed and that deputy ministers must give up foreign citizenship.

'The government may think it needs flexibility in setting salaries to attract talent,' Mr Wong said. But if what each was being paid was not disclosed, non-disclosure of salaries might end up applying to the top ministerial tier, compromising transparency.

Mr Wong said the government should explain why the appointees were not being paid the same.

'Do you pay someone less just because he comes from academia? And does someone deserve more because he is from commerce?' he asked.

A career civil servant, Mr Wong was appointed civil service minister in 2002, when former chief executive Tung Chee-hwa launched the 'accountability system'. He later assumed the commerce portfolio. He stepped down when Mr Tsang began his new term last July.

Mr Wong said he supported developing the 'accountability system' to strengthen support for ministers and preserve civil service neutrality.

But he rejected the view that there was nothing wrong with an international city such as Hong Kong having members of the ministerial system with foreign citizenship.

Five of the eight deputy ministers - or undersecretaries - have admitted having foreign passports or right of abode abroad. So far only two have taken steps to give them up.

Mr Wong said the appointees were supposed to be politically astute, but the citizenship controversy had called into question their competence.

The deputy ministers and nine political assistants were appointed in part because the government believes civil servants are not politically astute.

'When they cannot even generate confidence in their political ability, why would administrative officers [who make up the senior echelons of the civil service] feel it's fair?' Mr Wong asked.

'These people will become ministers one day and they are said to have commitment. Yet 10 years after the handover, they still hold foreign nationality. Are we really so lacking in talent that we can't get anyone other than those with foreign nationality?'