The qualifying criteria for presidential candidates must be updated, as these are no longer in line with the great responsibilities that the President faces, said Prime Minister Lee Hsien Loong.
"The weight of the job has increased," he said in his National Day Rally speech last night.
Currently, candidates must have either held key appointments in the public service, or had experience in the private sector running large and complex companies - defined in the Constitution as companies with a paid-up capital of $100 million.
But this criterion is "out of date", he said.
"Look at what the President is protecting," he said, citing figures on how the economy and reserves have grown in the last 25 years.
For instance, the Monetary Authority of Singapore's (MAS) official foreign reserves were $351 billion last year, up from $48 billion in 1990.
It is here that the President makes critical decisions and it is here that we need the President to be competent, be on top of the job, to be capable. And that is why we need the most qualified person.
PRIME MINISTER LEE HSIEN LOONG, on how the President has to make real and difficult choices on whether the Government's Budgets and spending proposals are sound and justified.
The companies used as a benchmark, such as Singtel and DBS, have also grown much larger.
Today, $100 million is "the wrong number", said Mr Lee.
"It is too small for a company to be considered even... the same kind of responsibility as (what) the President is doing here."
There are now also many more such companies: 2,000, compared with just 158 in 1993.
So running such a company is no longer comparable to the responsibility of being the President, he said, adding: "We've got to update this benchmark."
Having the right qualifying criteria is crucial because the President has the mandate to decide on the national reserves and key appointments, stressed Mr Lee.
The President must ensure that the government of the day does not fritter away Singapore's carefully accumulated reserves, and that the people appointed to key posts are capable, upright and will uphold the system.
He must, thus, have the right experience to decide whether the Government's budgets and spending proposals are sound and justified, and to judge the candidates for public-sector appointments.
These are "real and difficult choices" that the President must get right, said Mr Lee.
He raised the example of the global financial crisis in the late 2000s, when the Government sought the approval of then President S R Nathan to draw from the reserves for its annual Budget.
The Government wanted $5 billion to save businesses and jobs, and to guarantee all bank deposits in Singapore by backing them with $150 billion of Singapore's reserves.
"We were not certain whether the plans would work, whether they would be sufficient," he noted.
"The President had to judge whether the Government got it right, whether our recommendations were sound."
Mr Nathan and the Council of Presidential Advisers were briefed by the ministries and MAS.
He consulted the council, thought it over carefully, and gave the Government permission - which turned out to be the right thing, said Mr Lee.
Because of that intervention, Singapore's economy bounced back quickly once the outlook changed, and jobs were saved.
"So it is here that the President makes critical decisions and it is here that we need the President to be competent, be on top of the job, to be capable.
"And that is why we need the most qualified person," concluded Mr Lee.