The qualifying criteria to be president, set 25 years ago, need to be updated to ensure a private sector candidate for the role is qualified for, and capable of, doing the job, Prime Minister Lee Hsien Loong said.

In a television interview broadcast yesterday, he noted that the economy and size of the national reserves had multiplied around seven times.

But the key criterion for a private sector candidate - having run a large and complex company, defined as one with $100 million in paid-up capital - had remained constant.

In 1990, $100 million was a "significant threshold", with fewer than 200 companies fitting that category, meaning that a few hundred people qualified, Mr Lee said.

But today, he added, 2,000 companies meet that mark - and counting two to three persons who have been chief executive or chairman, "at face value, I should have 5,000 or 6,000 people who are qualified and capable of being president".

"But I don't believe all 5,000 or 6,000 of them actually have the experience and the relevant competence in their work in order to do the president's job," Mr Lee added.

The figure for paid-up capital has to be revised to a realistic level that is not too constraining, but gives a sense of the big decisions that have to be made as president, he said.

This criterion should also be revised regularly, perhaps every two terms, to adjust for inflation and the size of the economy, he added.

The Constitution stipulates that those who have held certain key appointments in the public sector qualify as presidential candidates. Mr Lee said this is "more or less self-adjusting because, if you're a minister of finance, as the economy grows, your job grows with it".

Asked about the view that changes to the qualifying criteria aim to disqualify those not seen as friendly to the Government, Mr Lee said his concerns were for Singapore's future in the next 30, 40 or 50 years, and not over individuals.

"We are looking at changes which are for the long term," he said, citing capable candidates and multiracial representation.

He added that even if qualifying levels are raised, he "cannot guarantee that nobody who is going to be difficult will become president".

"It is not possible because however, wherever, you cut off, there will be somebody, even a former minister or a former judge or somebody who may have run a very big company, (who) may have his views and may clash with the Government."

He said one way to prevent things going wrong is to have good people in politics: "It's not a guarantee but it's the ideal we have to aim for."

Chong Zi Liang