Dr Tan Cheng Bock's appeal against the High Court decision to dismiss his legal challenge on the upcoming presidential election will be heard on July 31.

Dr Tan, a former candidate in the previous presidential election in 2011, said in a Facebook post yesterday that the hearing in the Court of Appeal will be open to the public and begin at 10am.

In his post, he said: "I look forward to a final judicial clarification on whether the Government had correctly picked President Wee (Kim Wee) as the 1st of 5 presidencies to trigger a reserved election for 2017."

On July 7, the High Court ruled that Parliament was entitled to decide the timing of a reserved election, following changes to the Constitution to limit an election to a particular racial group when it has not been represented in the presidency for five continuous terms.

The changes to the law were made to ensure that the highest office in the land reflects Singapore's multiracial society.

The Government had 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.

However, Dr Tan Cheng Bock argued this was unconstitutional because Mr Wee was not popularly elected, and said the count should start from the term of President Ong Teng Cheong.

He contended that the reserved election should start in 2023 at the earliest.

But Justice Quentin Loh ruled that Parliament, ultimately, has the right to decide which presidential terms it would take into account.

He said the Constitution does not restrict Parliament to consider only presidents elected by citizens, and added that it also allows the term of a president elected by Parliament, in this case Mr Wee, to be included.