The issue of whether a Singapore male should be allowed to defer his national service (NS) has long been a hot-button one.

But there are few who quibble when the man in question is star swimmer Joseph Schooling.

Athletes and members of the public alike yesterday supported the Government's move to extend the 21-year-old's deferment till after the next Olympic Games in Tokyo, saying this is key for him to further improve and hopefully garner another gold medal come 2020.

"Sportsmen like to be consistent in their training to keep improving," said football coach Muhammad Khairil Asyraf Roslan, who heads the under-12 programme at the Junior Soccer School & League Arsenal School. "If he enlists before the 2020 Olympics, it might hinder his progress as a lot of time would be spent away from the pool."

Sailor Maximilian Soh, 28, who had a year-long deferment from 2007, said having the time and space to focus on his sport was crucial.

Defence Minister Ng Eng Hen yesterday said the Armed Forces Council had approved Schooling's request for deferment. This is Schooling's second: In 2013, he received permission to defer his NS till after the Rio Olympics.

Full-time NS deferments are rare. Approved sportsmen must have been assessed to be potential medal winners at global competitions. Others granted the privilege include swimmers Ang Peng Siong, Sng Ju Wei and Quah Zheng Wen, who last year was allowed to defer NS until the end of this month. The Defence Ministry yesterday said it has not received any application for Quah to be granted a further deferment.

The Government has maintained that such approvals must be the rare exception as the strength of the NS system rests on it being universal and fair. But this stance has come up against calls for more flexibility. Last year, Singapore National Olympic Council president Tan Chuan-Jin said he aims to "push the boundaries" and try to grow the pool of elite athletes obtaining deferment.

Yesterday, Dr Ng stressed that the conditions for NS deferment remain consistent, adding that Schooling has been "exemplary in fulfilling the raison d'etre for his deferment - he trained hard and met all performance milestones on his way to Olympic glory". But some parents hope Schooling's victory could spell a rethink on the authorities' part.

Mr Melvyn Ang, whose two sons are swimmers in the Singapore Sports School, said: "We hope the powers that be realise that age 18 onwards for a budding athlete is most important for growth and development, and that NS during this important stage will adversely affect their progress in their sport."

• Additional reporting by Amelia Teng