THE Secretary for Security, Mr Alistair Asprey, said that a phased programme for British National Overseas (BNO) passport applicants was the only way to ensure an orderly replacement of the British Dependent Territories Citizens (BDTC) documents, which become invalid in 1997. He ruled out the introduction of any kind of pre-registration for BNO applicants, saying a person could only retain his BNO status if a BNO passport was issued before July 1, 1997. ''The eligibility to apply right up to June 30, 1997, is an illusion. We cannot have 3.5 million people applying in the last few days or weeks or months,'' he said. Legislators had criticised the move, saying it denied the public the right to retain their BDTC passports until 30 June, 1997, as set out in the Joint Declaration. An early pre-registration system would allow applicants to reserve their BNO passports before 1997 while still holding their BDTC documents, they said.