Just a week after he unveiled a 200-page blueprint to keep the city disease-free, it is also understood Mr Tsang is considering a move to establish 'regional slaughterhouses'' for poultry as opposed to a much-talked-about central slaughterhouse.

The idea, similar to systems in place in many countries overseas, is perceived as a 'halfway house' that would allow slaughtered birds to get to markets in different districts quicker, offering customers fresher poultry.

The source stressed consultation with the poultry trade was still needed, but added: 'Mr Tsang is determined to eliminate the threat of bird flu. He feels the sale of live poultry has to stop but is very aware of opposition in the community.

'It's just a question of getting the right formula, with broad community agreement, to move to that end.'

Also in Team Clean's post-Sars blueprint released last weekend were plans for tougher penalties on repeat hygiene offenders and a crackdown on building owners and tenants who flout cleanliness standards.

'We cannot afford to face another major public health incident such as an avian influenza outbreak affecting humans. The consequences would be catastrophic,' Mr Tsang said in the report.

The plans have been met with howls of protest by poultry traders, who fear the livelihoods of several thousand people are at stake.

Initially, Mr Tsang is expected to propose the segregation of live poultry from customers at markets - one of the four preventive measures against human infection by bird flu viruses outlined in the blueprint.

But the option 'would not fully address the root of the avian influenza flu problem' because public health remains at risk during the daily transportation of 100,000 live chicken to 820 retailers in densely populated urban areas, the source said.

Mr Tsang said in his report: 'The potential contamination of the environment arising from the loading, unloading and delivery of live poultry and the drifting of small down feathers into the air will remain.'

The separation of live birds from the public at retail level would mean retailers would have to install glass or acrylic panels to separate the holding area for birds from the customers, who would only be able to choose the birds through the partition.

The government source said initial reaction from traders to this option was favourable, prompting the chief secretary to pick it as an interim measure before introducing a total ban on live poultry at retail markets while allowing the sale of 'warm' slaughtered birds. The source said regional slaughterhouses would shorten the time of delivery to 10 to 15 minutes, keeping the birds fresh and warm. The regional concept would remove the problem of having to find a suitable site for a central slaughterhouse, and could absorb many traders.

The Director of Food and Environmental Hygiene, Gregory Leung Wing-lap, said yesterday tests were under way to determine the ideal temperature birds should be when they reach markets. The source said officials fear supermarkets might monopolise the sales of warm poultry.