Mr S R Nathan spent his early years in a long and distinguished career in public service fighting for the rights of workers.

It was fitting then that 700 unionists from the labour movement were among the first out of more than 20,000 people who waited in line to bid Singapore's sixth and longest- serving president a final farewell as he lay in state at Parliament House.

With the unionists were several labour MPs as well as labour chief Chan Chun Sing, who said that Mr Nathan was "an integral part of our labour movement".

He built a strong foundation for unions, Mr Chan said, adding: "We will dearly miss him. But what he has left us will be with us for a long time, for many generations to come."

Foreign Minister Vivian Balakrishnan led a group from the Ministry of Foreign Affairs.

Mr Nathan spent years in the world of diplomacy and was, among other appointments, First Permanent Secretary in the ministry, High Commissioner to Malaysia and Ambassador to the United States.

Head of civil service Peter Ong, who was with a delegation of civil servants, described Mr Nathan as a "civil servant exemplar" who placed the interests of the nation above self.

He cited the hijacking of the Laju ferry by terrorists in 1974 - when Mr Nathan helped secure the release of hostages by accompanying the terrorists on a flight to Kuwait to guarantee their safe passage.

Various religious groups also headed to Parliament House to acknowledge Mr Nathan's contributions not just to their communities but also to a multi-religious society.

Mufti Fatris Bakaram said Mr Nathan never failed to keep abreast of concerns and developments in the Malay-Muslim community.

"This leadership style is what struck me the most and is the most endearing trait of Mr Nathan."

Mr Chung Kwang Tong, an administrator at the Taoist Federation, said: "He would always remind us of the importance of the trust we must have between the different religious groups. This is something we will always bear in mind."

Others who came to pay tribute included Prime Minister Lee Hsien Loong and Mrs Lee, Health Minister Gan Kim Yong and Acting Minister for Education (Higher Education and Skills) Ong Ye Kung.

Mr Lee later received Japan's Prime Minister Shinzo Abe and his wife, who made a brief stopover in Singapore en route to Kenya.

It was a day that transcended politics as opposition politicians turned up to honour Mr Nathan.

Former MP Chiam See Tong, who was in a wheelchair, was helped to his feet by his wife, former Non-Constituency MP Lina Chiam, to pay his respects. Later, a group of Workers' Party MPs led by party chief Low Thia Khiang and party chairman Sylvia Lim arrived and bowed before the casket.

The former president's final journey to Parliament House began at about 8.40am yesterday when the casket bearing his body left his Ceylon Road home. It arrived at 9am and was received by Speaker of Parliament Halimah Yacob.

President Tony Tan Keng Yam and his wife, Mrs Mary Tan, arrived shortly after and were the first to pay their respects after nine officers transferred the casket onto the bier.

The public then began streaming into Parliament House.

Among them was undergraduate Jorden Karma Senapati, 23. He had been too early to secure a place, having arrived with a friend at 11pm on Wednesday, and had to wait outside Parliament House.

They lost their position at the head of the queue yesterday morning after leaving the line for a short while.

But they returned and still managed to be among the first 10 to file past the casket when Parliament House's doors opened at 10am.

Mr Senapati said he wanted to queue early in order to avoid a repeat of the long wait he faced last year, when he lined up to pay his respects to the late founding prime minister Lee Kuan Yew.

"Last year, I started queueing at 8pm and by the time I got home it was 10am the next day," he said.

Administrator Alice Tan, 60, felt that the organisers were better prepared after last year's experience.

"I was prepared to wait for up to three hours, but the queues were very smooth-going, and we were in and out in less than half an hour."

Indeed, tentage was set up at the Padang to shelter waiting crowds, umbrellas were kept at the start of the queue in case of rain and bottles of water were offered at various points of the line. Wheelchairs were also available. One of those who made use of that facility was Madam Yeo Kheng Neo, 94.

But when she reached the bier, she stood up in a mark of respect to Mr Nathan.

Her son, Mr Tay Kheng Hee, 62, said: "When deciding to come, I asked myself, does he make me feel proud to be a Singaporean? I felt proud, so I came."