The idea of extending the Mass Rapid Transit system to Changi Airport was reconsidered when Terminal 3 of the airport was being built. Earlier plans had long been made for a new line branching off from the existing East West line at Tanah Merah, with some conceptual plans showing a tentative route alignment up to the airport along Airport Boulevard, continuing beyond the airport to Changi Point, before turning southwest back towards the city along the eastern coasts. The plans were finally announced by then Deputy Prime Minister Lee Hsien Loong on 15 November 1996. However, the new route alignment showed a deviation from previous plans, where the final plan involved in building only the first two stations of Expo, and Changi Airport, the latter being the underground station built between Terminal 2 and Terminal 3. The alignment of the station at the airport also switched perpendicularly to an east-west direction, such that the station leads to two of the terminals directly from either end of the station. The stations' designs were unveiled on 10 February 1998 with construction starting on 29 January 1999. Expo and Changi Airport were opened on 10 January 2001 and 8 February 2002 respectively and currently operates under a shuttle service. Prior to 22 July 2003, train services from Boon Lay commences after the opening, but were later reverted to shuttle services due to low patronage. On 25 May 2019, it was announced that the Changi Airport Extension will be converted to become part of Thomson-East Coast line Extension (TELe) by 2040.