SINGAPORE - When Singapore's founding prime minister Lee Kuan Yew spoke in Mandarin for the first time at a political rally in 1955, behind a row of shophouses in Bandar Street Square, it was Mr Jek Yeun Thong who wrote the one-page speech.

A journalist with then Chinese broadsheet Sin Pao, Mr Jek was deemed a "friendly reporter" by Mr Lee, who recruited him for the task.

Mr Jek would later enter politics, playing an important role in cultivating the Chinese ground for the People's Action Party.

On Sunday (June 3), the former minister, one of two remaining PAP Old Guard leaders, died in his Bukit Timah home. He was 87.

Mr Jek is survived by his wife, Madam Huang Kek Chee, 84, two sons Kian Jin, 59, and Kian Yee, 55, and five grandchildren.

Son Kian Yee said Mr Jek had been quite frail since his last public event at Singapore's SG50 National Day Parade celebration in 2015.

"Old age was catching up with him and (he had) various illnesses. He passed away peacefully in his sleep and the family was with him till the end," he told The Straits Times on Wednesday (June 6).

He added that the family, in accordance with Mr Jek's wishes, held a private wake, and the funeral was on Tuesday.

The younger Mr Jek said his father had wanted a low-profile and quiet departure, like the farewell described in one of his favourite poems by Chinese poet Xu Zhimo, Taking Leave Of Cambridge Again.

The last stanza describes a quiet, unobtrusive farewell, without "taking away a single cloud".

Said the younger Mr Jek: "This encapsulates his philosophy, which he had often spoken to us about, especially in the last years of his life. He came quietly and wanted to go quietly."

As a mark of respect, and in recognition of Mr Jek's contributions to the nation, the state flag on all government buildings will be flown at half-mast on Thursday, said a statement from the Prime Minister's Office on Wednesday.

In a letter to Mr Jek's widow, Prime Minister Lee Hsien Loong said Mr Jek's death is a deep loss to the nation.

He added that one of Mr Jek's biggest political contributions was to help mobilise the Chinese-speaking ground to support the PAP's vision of a non-communist, multiracial Singapore.

Mr Jek was among the 10 men in the founding government to have inked the Independence of Singapore Agreement on Aug 9, 1965.

From his teenage years, he had been politically aware, and was a student union leader and editor of a wall newspaper, which is put up on walls, when studying at The Chinese High School.

But in 1950, he was expelled from school for anti-colonial activities. He was monitored by the Special Branch and blacklisted by the British colonial government and, as a result, could not continue his studies in any school in Singapore.

In 1954, he joined the two organisations that would lead him down the path of politics: left-wing Chinese-language newspaper Sin Pao and the PAP.

Although Mr Jek had left-wing sympathies, and was arrested for a spell in 1957, he later supported the non-communist camp, and helped the PAP write speeches and pamphlets in Chinese to reach out to the Chinese ground.

Recounting his first-ever Mandarin rally speech, the late Mr Lee Kuan Yew credited Mr Jek with playing a crucial role.

"A friendly Sin Pao reporter called Jek Yeun Thong drafted two paragraphs for me, and then spent several hours coaching me to read a speech that took only three minutes to deliver. But the crowd was with me, and they cheered me for the effort," Mr Lee Kuan Yew had said.

In 1959, Mr Jek was appointed Mr Lee's political secretary.

He entered politics in 1961, contesting and losing in his first election, the Hong Lim by-election in the same year. He later won in Queenstown in 1963, and was appointed Minister for Labour.

In 1960, he was appointed as the government representative, along with Mr Lee Khoon Choy, who was a PAP politician, to the Joint-Government-University Liaison Committee to reform then Nanyang University, known as Nantah.

Degrees from the university had not been officially recognised since 1959, because of doubts about academic standards. It affected the employment opportunities of students and frustrated them.

The issue and Chinese education in Singapore became a flashpoint in the 1963 general election, with Nantah seen as supporting the Barisan Nasional after a sizeable number of its graduates ran under the party's platform.

Mr Jek's involvement in the earlier negotiations had helped to fend off accusations that the PAP was against Chinese education, said Lee's Lieutenants, a book on Mr Lee Kuan Yew and the Old Guard.

In handling this episode, Mr Jek had stood firm for the PAP's vision of a multicultural Singapore, championing a Chinese identity that was divorced from communism and chauvinism.

Later on, as a minister, Mr Jek would continue to champion Chinese education and Chinese standards. He once decried the declining standards of Chinese, criticising the use of hanyu pinyin and the adoption of simplified Chinese characters.

As Minister for Labour, he was put in charge of building trust with the Chinese-speaking unions as well.

He also drafted and passed the 1968 Employment Act, which changed the law to give employers more power to decide on matters of staff transfer, promotions and retrenchment exercises.

This labour reform laid the groundwork for labour relations to become more harmonious, paving the way for Singapore's industrialisation.

Mr Jek was also Minister for Culture from 1968 to 1978 and Minister for Science and Technology from 1976 to 1980.

As Minister for Culture, the former journalist pushed through the Newspapers and Printing Presses Bill in Parliament. The new law proposed the issuance of management shares, which has greater voting rights, for newspapers that want to be publicly listed.

During the debate on the Bill, he had said: "The sole purpose of this legislation is, I emphasise, merely to safeguard our national interest and well-being of our citizens by preventing our newspapers from being used as instruments for subversion."