Any move to abolish the elected presidency may well not work - even if passed by Parliament.
Two lawyers suggest such a scenario as an example of how the separation of powers between the executive, the legislature and the judiciary is a basic structure which cannot be changed by altering the Constitution.
Mr Calvin Liang, of Tan Kok Quan Partnership, and Ms Sarah Shi, of the Attorney-General's Chambers (AGC), write in the current issue of The Law Society's Law Gazette that recent cases have shown courts are beginning to recognise this basic structure.
They said: "The basic structure doctrine posits that a Constitution has certain written and unwritten features so fundamental that they cannot be abrogated through constitutional amendments."
Ms Shi, an Oxford University graduate, said the article, The Constitution Of Our Constitution: A Vindication Of The Basic Structure Doctrine, reflected her personal views and not the AGC's.
The elected presidency was raised in Parliament in May when an MP suggested scrapping the post and returning the role to its original ceremonial position as head of state.
The post was created when Singapore became independent in 1965. The president was chosen by Parliament but the role became an elected office with key powers, following amendments to the Constitution in 1991.
It has been argued that what Parliament gave, Parliament can take back.
But the authors point out that this confuses the issue of whether the basic structure can be changed as a matter of political reality with whether it would be lawful to abolish such a power.
They added: "More fundamentally, the basic structure is not tied to the source of the Constitution but to its core function as a power-limiting device."
The authors argue that the basic structure is implied and arises from the very nature of a Constitution and not by decree from the legislature or the courts.
They point out that the basic structure doctrine was expressly rejected by the High Court when first raised in a constitutional court case in 1989.
However, they cite a recent string of cases in which the courts have begun to recognise it.
These include Tan Eng Hong's bid for a judicial review of the constitutionality of section 377A of the Penal Code, seen as an anti- gay law, and the bid by Madam Vellama Marie Muthu for a court ruling on the prime minister's discretion on when to call a by-election when a seat falls vacant.
In addition, then Chief Justice Chan Sek Keong recognised this basic structure as part of the Singapore Constitution in the course of dealing with the case of Mohammad Faizal Sabtu, a convicted drug offender, in 2012.
Mohammad Faizal raised the question of law as to whether Parliament intruded into judicial power and violated the principle of separation of powers by requiring the court to impose a mandatory minimum sentence for a drug offence.
In addressing the question, the court looked at the Singapore constitutional framework, which is based on the British model. This accepts that a Constitution is based on certain unwritten basic principles, such as the separation of powers.
In effect, this means any move to abolish the elected presidency by constitutional change, even if supported by a referendum, could run into basic structure objections as it may "fundamentally alter the separation of powers".
This article was first published on Sep 11, 2014.
Get a copy of The Straits Times or go to straitstimes.com for more stories.