The report also said the Government had considered an alternative for the rail to run along the coast between Tuen Mun and Tsuen Wan, eventually stopping at Cheung Sha Wan.

A third option on extending the Tin Shui Wai link to Tuen Mun has also been considered, but this would again push the costs to $12 billion.

''It is impossible to introduce a new system when we know that it will destroy the existing one,'' he said.

It is estimated that the business of the LRT will drop 20 per cent in the initial stage of the heavy rail service, he added.

Mr Leung, who is heading for the post of the Secretary for Education and Manpower in June, said the Government had also considered the cost-effectiveness of the suggested routes.

Quoting figures from a government study, he said the latter route was twice as expensive as the proposed one.

A study by the Government shows that project cost would surge from $6 billion to $12 billion if the Government opt for the link which started at Tuen Mun.

Mr Leung maintained that it was not worth doubling the investment as the Tuen Mun-Tsuen Wan link would only save commuters 10 minutes for every trip to Central.

It takes 50 minutes for a Tuen Mun resident to commute to Central via the proposed Yuen Long station while 40 minutes will be needed for the latter proposal.

Miss Ida Leung Pik-fu, public affairs manager of the LRT, said the extension of the heavy rail service to Tuen Mun would affect the company's business. But the LRT could also benefit from the improved length between Tuen Mun and Kowloon.

''We are talking about a link from the urban area to Tuen Mun and this would bring more visitors to the northwest New Territories. From a business point of view, this is helpful to us.'' In response to Mr Leung's speech, Tuen Mun District Board member Mr Yim Tin-sang and legislator Dr Tang Siu-tong urged him to reconsider the proposal at the end of a three-month consultation period in June.

Both of them said the Government should not trade the traffic convenience of Tuen Mun residents for the LRT's business.

Elected legislator, Dr Tang, who represents the New Territories West constituency, was disappointed at Tuen Mun's exclusion from the coming heavy rail development project.

The Government has only suggested that Tuen Mun be included in a long-term proposal to connect both Tin Shui Wai and Tuen Mun to Yam O in the Outer Western Corridor project.

However, it is not sure when it will be built as the report stated that due to its relation with the port development programmes, ''No dates for construction have therefore been proposed.'' Mr Yim described the proposal as ''short-sighted''.

He criticised the Government's failure to take into account the future development of Tuen Mun.

''What about the proposed Zhuhai-Tuen Mun Bridge? The Government has failed to take this into account and, if the link between Hongkong and China is approved, we will see an additional traffic load to Tuen Mun.'' About 70 per cent of the Tuen Mun population works in the urban area and there is an immediate need to improve the transport link with Kowloon and Hongkong, he said.

Mr Yim also doubted whether the ability of the LRT to cope with the growing Tuen Mun population in a few years' time.

He said the design of the LRT platform had limited any plans to expand its passenger capacity.

Responding to this, Miss Leung said the company was sure that it could meet the demand until the 1996-97 year.