POLICE have warned pig farmers that they will take firm action if their protest outside the Legislative Council today gets out of hand. The New Territories farmers have threatened radical action, including releasing what they call ''secret weapons'', in the campaign against regulations tightening control on waste disposal. Chairman of the Hong Kong Livestock Industry Association, So Ying-kiu, said one of their plans was to release pigs and poultry and dump manure outside the chamber. Similar action would also be taken outside the offices of the Environment Planning and Lands Branch in Murray Building and at Southorn Centre, Wan Chai. Mr So has refused to apply for a licence from police for the protest, despite warnings of prosecution. ''If they [the police] won't allow us to go, I will fight against them at whatever cost,'' Mr So said. But Central District Commander Hui Chiu-yin warned the farmers they must comply with licensing conditions if they wanted to demonstrate outside Legco. Mr Hui said unnecessary conflict occurred when the farmers held a protest on Monday because they had ignored certain conditions. Three hundred farmers staged a mock funeral for the two government officials responsible for the waste control legislation. ''It is our policy to allow people to assemble and express their views in a peaceful manner,'' Mr Hui said. ''But demonstrators must comply with licensing conditions and co-operate with the police for the well being of the general public. ''If protesters threaten public order, police will be obliged to take firm action to enforce the law.'' The farmers' dispute with the Government dates back to 1987, when the Livestock Waste Control Scheme was enacted to curb the 2,300 tonnes of pig and chicken waste dumped daily into rivers and streams. However, Mr So said his pig farm did not pollute the environment because he had spent more than $200,000 on new equipment to separate the solid and liquid waste. The system includes filtering, sedimentation and emission. Waste water, which has filtered out 90 per cent of the solid waste, is used for cultivation while the sediment is fermented as fertiliser. ''Though the farmers have all agreed to use this system to minimise pollution, the heartless Government does not accept our proposal,'' Mr So said. Mr So, 55, has raised pigs in his 10,000 square feet farm in Fanling since 1962. A father of three sons and two daughters, Mr So runs the farm alone because his children either have migrated to Canada or moved to the urban areas. He spends $50,000 to raise 500 pigs, which bring a $300 net profit for each pig. However, Mr So, the leader of 2,000 farmers since 1986, said he would close the farm if the Government passed the regulations. The Government has rejected the farmers' proposed compensation of about $200 for each square foot. It has agreed to give an ex-gratia allowance to cease business. ''I can't use the pigs' waste as fertiliser anymore which means I have to spend an extra $27,000 to buy fertilisers every two months,'' Mr So said.