S. Iswaran, known for helping bring Formula 1 to the financial hub, resigned in January after being hit with dozens of charges as part of a corruption probe, including accepting gifts worth hundreds of thousands of dollars.

He will stand in a trial deemed by observers to be one of the most politically significant in the city-state's history, and which risks damaging the reputation of the ruling People's Action Party (PAP) before general elections expected to be held by the end of the next year. 

Iswaran resigned from the party after being given formal notice of the charges against him, but pleaded not guilty to them.

Most of the 35 charges against the 62-year-old relate to corruption -- with an allegation involving a government contract carrying up to seven years in jail, but he also faces one charge of obstruction of justice.

Among other accusations, he is alleged to have accepted gifts from two businessmen worth more than $300,000.

Those included tickets to high-profile sporting events and stage shows from Malaysian hotel tycoon Ong Beng Seng, one of Singapore's richest people. 

Ong, the managing director of Hotel Properties Limited, was arrested the same day as Iswaran in 2023 but has since faced no punishment.

The transport minister is also accused of accepting bottles of whiskey and golf clubs from a top director at a construction company, who has not been charged with any offence.

Most of the charges against Iswaran have been levelled with a rarely used criminal law that states it is an offence for public servants to accept objects of value from figures they officially work with.

Iswaran's lawyers claim the businessmen are his close friends and he could accept the gifts in a personal capacity. The former minister rejects the charges and claimed innocence in his resignation letter.

Singapore's former prime minister Lee Hsien Loong said at the time of Iswaran's resignation that he had pledged to return money received as part of his salary and allowances since his arrest.

Cabinet ministers are paid salaries comparable to the top earners in the private sector to deter corruption.

Lee has previously admitted that his long-ruling PAP had "taken a hit" after a spate of political scandals.

Last year two PAP legislators resigned because of an affair.

Before that, two heavyweight cabinet members were investigated for allegedly getting favours in their rental of sprawling colonial-era bungalows, but were subsequently cleared.

Prime Minister Lawrence Wong, who succeeded Lee, has said the PAP's anti-corruption stance is "non-negotiable".

Singapore's last political office holder on trial for corruption and charged was Wee Toon Boon in 1975, accused of taking bribes worth more than $600,000, according to local media.