Every political system has its strengths and weaknesses, and Singapore conceived the institution of the elected presidency because its parliamentary framework, by itself, may not provide sufficient protection for the nation's reserves, Deputy Prime Minister Teo Chee Hean told the House yesterday.

He noted that some have argued that Parliament provides the best safeguard on this front, but countered that there is little or no incentive for lawmakers to resist appeals from a government should it decide to indulge in populist spending.

"Indeed, the call, from both sides of the House, will often be to do more," he said at the start of the debate in Parliament on proposed constitutional amendments regarding the highest office of the land.

When passed, the Constitution of the Republic of Singapore (Amendment) Bill will, among other things, tighten the eligibility criteria for presidential candidates, ensure that members of racial minority groups are elected from time to time, and give more weight to the recommendations of the Council of Presidential Advisers (CPA).

Mr Teo cited Greece and Australia as "cautionary tales of elections descending into auctions, with political parties competing with each other to promise greater largesse from the nation's coffers".

"The elected presidency plays an important custodial role in safeguarding our key assets, in a way a purely parliamentary process cannot," he said.

"It also deters political parties from making wild promises at parliamentary elections. They know that even if they come to power, they cannot splurge our past reserves on populist measures."

This custodial role was put into action during the 2008 global financial crisis, Mr Teo pointed out, when the Government sought the approval of then President S R Nathan to use nearly $5 billion of past reserves to save businesses and jobs, and to guarantee about $150 billion of bank deposits.

President Nathan gave his approval after examining the request and consulting the CPA. The sum drawn down was returned to the past reserves by 2011.

The Bill comes after a nearly year-long process that began when Prime Minister Lee Hsien Loong first raised the need for a review of Singapore's political system during the debate on the President's Address in January, and convened a Constitutional Commission to review the elected presidency.

The commission's report was released in September, and the Government responded in a White Paper that broadly accepted the commission's recommendations.

One key change stipulates that a candidate from the private sector must have helmed a company with at least $500 million in shareholder equity to qualify, up from $100 million in paid-up capital now.

Another significant proposal is to reserve an election for a particular racial group if there has not been a president from the group for the five most recent presidential terms.

Mr Teo reiterated the need to update the eligibility criteria, noting that "the economic environment we live in is very different from when the elected presidency was introduced in 1991".

The proposed changes will ensure the criteria are periodically reviewed so that presidential candidates continue to have the necessary expertise to handle complex financial matters, as the economic situation changes over time.

During public hearings held by the commission in April and May, several contributors argued that the stringent eligibility criteria for the presidency seemed to be far more exacting than the eligibility criteria prescribed for the prime minister. However, they later conceded that this was a false comparison, Mr Teo noted, as the PM assumes office through an entirely different process from the president's.

The PM is elected as an MP during parliamentary elections, leads the political party that wins the majority of seats in Parliament, and commands the support of a majority of elected MPs.

"These requirements mean that there is a multi-layered filtering process where a person's abilities are tested before he is likely to become prime minister," he said.

The president, however, is elected directly and therefore there needs to be a baseline of experience and expertise that a candidate should possess, Mr Teo added.

Concluding, he likened the elected presidency to a ship's ballast that prevents it from rolling uncontrollably and capsizing in rough seas. But too much ballast will affect a ship's speed and agility.

"Our nation, like a ship, needs an optimal amount of ballast - enough to keep us stable, but not so much as to render us sluggish and unresponsive to change," he said.