By Xinghui Kok
SINGAPORE (Reuters) - Singapore on Tuesday named the three candidates running for the largely ceremonial role of president, kick-staring an electoral process that is seen as a referendum on the party that has ruled the island nation for more than six decades.
The candidates include former Deputy Prime Minister Tharman Shanmugaratnam, 66, widely regarded as the pick of the ruling People's Action Party (PAP), even though the party has no official say in the voting process nor has it named a preferred candidate.
Earlier this month, Prime Minister Lee Hsien Loong said the PAP, which has ruled Singapore since 1959, had "taken a hit" over a spate of scandals including a graft probe and senior lawmakers' resignations which shocked the city-state otherwise known as a haven of political stability.
The other two candidates are Ng Kok Song, 75, the former chief investment officer at sovereign wealth fund GIC, and Tan Kin Lian, 75, a former chief executive of insurer NTUC Income.
Whomever wins will take over from Singapore's first female president, Halimah Yacob.
Halimah was the only candidate to qualify for election in 2017 after parliament amended the constitution a year earlier with the aim of bringing more ethnic diversity to the role.
The change allowed members of only one ethnic group to run for president if no one from that group had been in the role for five consecutive terms. In 2017, applications from four candidates were rejected, sparking a rare protest.
About three-quarters of Singapore's 3.5 million citizens are ethnic Chinese, with the rest of the population ethnic Malays, ethnic Indian or Eurasian.
This year, the election was opened to all ethnicities.
More than 2.7 million Singaporeans will vote on Sept. 1 in what is the third presidential election since a 1991 act gave the public the right to choose.
Singapore's strict qualifying criteria has meant that all elections bar the vote held in 2011 and 1993 were uncontested.
Tan was also one of four candidates who ran for president in the 2011 election.
Singapore's president sits for a 6-year term.
($1 = 1.3568 Singapore dollars)
(Reporting by Xinghui Kok, Additional reporting by Chen Lin; editing by Miral Fahmy)