Green groups have urged Chief Executive Tung Chee-hwa not to authorise work on a controversial rail line even if an environmental impact assessment report on the project is approved. They also attacked Secretary for Transport Nicholas Ng Wing-fui for exerting undue pressure this week on Environmental Protection director Rob Law to approve the assessment report on the Lok Ma Chau spur line. Six green groups yesterday met Secretary for Food and Environment Lily Yam Kwan Pui-ying to discuss the proposal. They voiced fears over probable destruction of the natural bird habitat in Long Valley - the resting and feeding place for more than 200 species of migratory birds - if the 7.4km spur line linking the Lok Ma Chau border point and Sheung Shui was built. Conservancy Association president Ng Cho-nam said Mrs Yam had said she would consider the group's views. 'But she said she couldn't go further on that as the project is being considered by the Director of Environmental Protection,' Mr Ng said. He also said that even if the Environmental Protection Department accepted the report, Mr Tung should veto the project when it was presented to the Executive Council for approval. 'The spur line would lead to irreversible loss of habitat and that is something that could seriously damage the international image of the SAR,' he said. Mr Law is due to decide in two weeks if an environmental permit should be issued to the Kowloon-Canton Railway Corporation. But under the Railway Ordinance, work could only start after authorisation by the Executive Council, which is expected to make a decision by the end of the year. On Wednesday, Mr Nicholas Ng urged Mr Law to approve the project so that the spur line could ease rising cross-border passenger traffic. Plato Yip Kwong-to, assistant director of Friends of the Earth, said Mr Ng's remark was inappropriate, especially when most senior officials had been keeping silent over the issue. 'Even Lily Yam herself didn't say much about the project in the meeting. She spent most of the time listening to our views,' he said. A Food and Environmental Hygiene Bureau spokesman said it would consider green groups' views, and conservation would be a priority in the coming year.