THERE is no turning back on Container Terminal 9 (CT9) and it needs to be built even though it has been hit by delays, the Secretary for Economic Services, Gordon Siu Kwing-chue, said yesterday. He said it was impossible to skip the building of CT9 and wait for CT10 on Lantau. The United Democrats have been asking the Government to scrap the project and speed up the Lantau port development. They say CT9, which is to be built on Tsing Yi Island, will worsen the already bad traffic in the Kwai Chung and Tsing Yi areas. The project has been bogged down for a year after being dragged into the Sino-British dispute. China warned last December that, without its approval, CT9 contracts awarded by the Hong Kong Government might not be honoured after 1997. The first berth of CT9 was originally expected to be completed in August 1995. The Government now says it will not be ready until the end of that year. At yesterday's Economic Services and Public Utilities Panel meeting, United Democrat Lee Wing-tat said China was unlikely to endorse the project until early next year, which meant construction could only start by the middle of 1994. If that were the case, CT9 would be completed only six months ahead of CT10. That would defeat the purpose of building CT9, which was meant to alleviate the heavy demand that would arise between mid-1995 and 1997, he said. But Mr Siu said: ''Abandoning the project will affect the whole of Hong Kong's port development.'' There was a need to go ahead with CT9 even if it would only come on stream a few months earlier than CT10. ''China has never said it opposed the building of CT9,'' he said. Mr Siu said questions raised by the mainland so far were technical ones. He was hopeful that China's blessing for the project would come. CT10 could only operate after the Tsing Ma and Kap Shui Mun bridges, scheduled for completion in mid-1997, were ready, he said. If CT9 were shelved, the existing port facilities would come under great pressure to cope with the rising demand. Port Development Board Secretary Tony Clark said Hong Kong needed six additional berths by mid-1997 and CT10 could only provide four. He said he did not envisage serious delays in the opening of CT9. Mr Clark stressed the terminal was important to the whole port development because the land adjacent to it would provide much-needed back-up space, for example, to store containers or for better road circulation. He said there was no deadline for the commencement of the CT9 project.