Five judges, instead of the usual three, will hear Dr Tan Cheng Bock's appeal on the upcoming presidential election on Monday.
They include Chief Justice Sundaresh Menon, who previously noted that the Court of Appeal could be expanded to hear selected cases of jurisprudential significance.
CJ Menon also chaired the Constitutional Commission convened last year to update eligibility criteria for the elected presidency and ensure it reflects Singapore's multiracial society.
Dr Tan said in a Facebook post last night that some had asked whether CJ Menon should hear the case, given his role on the commission.
He said he welcomed the involvement of CJ Menon, adding: "In my view, no other judge knows more about the subject than the CJ.
"It is, therefore, proper and beneficial to Singaporeans that he is available to address questions on the reserved election scheme and its spirit and purpose," he said.
Dr Tan noted that last week, the court wrote to the Attorney-General as well as to his lawyers, led by Senior Counsel Chelva Rajah of Tan Rajah & Cheah, to ask if either party had any objections to CJ Menon sitting at the hearing. Both sides said there were none, he said.
"Having five judges is significant," he added. "It points to the importance of the constitutional issues for clarification."
The Constitutional Commission had recommended reserving an election for members of a racial group if it had not been represented in the presidency for five continuous terms. This was accepted by the Government and passed by Parliament, which decided this year's election should be reserved for Malay candidates.
The Government started its count of the five terms from the term of President Wee Kim Wee, who was in office when the elected presidency took effect in 1991. There have been four other terms since, including that of current President Tony Tan Keng Yam.
But Dr Tan Cheng Bock, who contested the 2011 presidential election, had argued this was unconstitutional as Mr Wee was not popularly elected. He said the count should start from President Ong Teng Cheong, so the reserved election should start in 2023 at the earliest.
But Justice Quentin Loh ruled on July 7 that Parliament, ultimately, has the right to decide which presidential terms to take into account.
He said the Constitution does not restrict Parliament to consider only presidents elected by citizens when deciding the timing of an election, and added that it also allows the term of a president elected by Parliament, in this case Mr Wee, to be included.
CJ Menon had, in 2014, said the expansion of the apex court would allow "difficult or unsettled issues" to be resolved "with the benefit of the collective wisdom and insights of a larger pool of judges".
Also in the court for Monday's hearing, which will start at 10am, are Judge of Appeal Judith Prakash, Judge of Appeal Steven Chong, Justice Chua Lee Ming and Justice Kannan Ramesh, according to the Supreme Court hearing list.
