Lawyer Gerard McCoy said the ban disenfranchised the 'talent of the civil service' and violated the Bill of Rights. Mr McCoy represents the Senior Non-expatriate Officers Association and its applicants Leung Chi-chiu, Ching Kam-cheong and Martin Cheung Kin-keung.

The officers are among the 1,200 directorate-grade officers who, unlike the other 95 per cent of government workers, are not allowed to serve on the Selection Committee.

'The classification is dependent solely on income,' Mr McCoy told the court. 'Nothing else distinguishes them.' To qualify as a directorate officer, a civil servant must earn a minimum of $86,650 a month.

Mr McCoy described the applicants as 'distinguished people in themselves, but hardly a threat to the political safety of Hong Kong'.

Mr Leung, 38, is a Health Department consultant, Mr Ching, 44, is a Transport Department chief engineer and Mr Cheung, 44, is chief engineer (civil) for the Housing Department.

Mr McCoy pointed out participation in the Selection Committee should not be seen as a political activity.

Mr Justice Sears scheduled the landmark hearing for September 10.

Association spokesman Ma Siu-leung said they had high hopes of having a court ruling before the September 14 deadline for nominations, as the court had expressed understanding about the importance of the case.

Chairman Hui Kwok-hung said the association wanted the guidelines amended to allow officers at directorate grade D3 or below to sit on the body.

A senior official is to appear in court this morning to present the Government's position.