TELEPHONE lines look likely to be tangled with callers facing delays and false engaged tones because few people are using the '2' prefix which becomes compulsory from June 1 From midnight on May 31, all calls without the 2 will be connected to a message telling callers to redial using eight digits, ending the dual access period that started on January 1, the official '2' day. Network operations director William Cheung Kam-hung said yesterday two-thirds of people were still not using the 2. 'When they have to, they will. Many people recognise they can call both the numbers [with or without the 2] and they are a bit lazy,' he said. But if everyone forgets, increasing the number of calls in the busy daytime by two-thirds from six million an hour to 10 million could lead to call queuing, he said. 'People could experience a bit of delay in getting the dial tone, or accessing a certain area they could get a busy tone,' he said. If some exchanges were particularly busy, the computer-controlled system could route calls through alternative exchanges, he said. 'But we don't expect a lot of problems,' he said. The change-over is part of the expansion of the telephone system to accommodate more telephone numbers and the end of Hongkong Telecom's monopoly on domestic calls on June 30. From July 1 three new fixed-line operators - New T & T, New World Telephone and Hutchison Telecommunications - can start offering competitive services, although analysts do not expect immediate changes for consumers. The companies say delays in issuing licences and agreeing connection terms mean new services will come in gradually over the next few months.