Separately, Hong Kong's biggest labour union said it would use its votes on the Election Committee, which selects the chief executive, to force Mr Tsang to present a timetable for the introduction of a minimum wage.

The new medical alliance, which represents 1,500 pharmacists, plans to field nine candidates in the health services sub-sector election. The sector has 20 seats for pharmacists and nurses.

Ng Kim-wah, president of the Society of Hospital Pharmacists of Hong Kong, said the constituency candidates would make the separation of drug dispensing and medical treatment an election issue. The other two groups are the Pharmaceutical Society of Hong Kong and the Practising Pharmacy Association of Hong Kong.

Dr Ng said there had been repeated incidents in which patients died because of doctors' mistakes in drug dispensing over the past year.

'We will miss the chance to arouse public attention on this pressing issue if we don't speak up this time,' he said.

Meanwhile, Wong Kwok-kin, chairman of the Federation of Trade Unions (FTU), said it would maintain its demand for the early introduction of a minimum wage and maximum working hours when choosing its candidate for chief executive.

But he added that this issue was not the only consideration for choosing a candidate.

FTU vice-president Chan Yuen-han warned that she and the other two FTU legislators representing the labour constituency - Kwong Chi-kin and Wong Kwok-hing - would not back Mr Tsang's bid for a second term if he did not pledge to legislate for a minimum wage for security guards and cleaning workers.

'Our colleagues at the FTU know our position very well,' she said.

Mr Tsang, who last year pledged to study the possibility of a minimum-wage law, said last Thursday he was not optimistic that a consensus could be reached with employers and worker representatives.

The 300,000-strong FTU won 30 out of the 40 seats in the labour sub-sector in the 2000 Election Committee polls. The remaining 10 were won by the Federation of Hong Kong and Kowloon Labour Unions (FLU).

Mr Wong expected more intense competition for the seats in the labour sub-sector election scheduled for December 10, because the number of trade unions had increased from 594 in 2000 to 686 at the end of last year.

A total of 455 unions registered as voters for the labour constituency in 2000. Of the 686 unions, 158 are affiliated to the FTU, compared with 136 in 2000.

Sixty-eight unions are linked to the Confederation of Trade Unions, compared with 47 in 2000. It boycotts the committee polls.