Founding Prime Minister Lee Kuan Yew once told former transport minister Raymond Lim that helming the transport portfolio was "a thankless job".

In "quintessentially Lee Kuan Yew fashion", he then added: "But someone here has to do it."

Mr Lim recounted this encounter at the introduction of the PAP's East Coast GRC slate for the coming polls yesterday. He is retiring from politics, and his successor in the Fengshan division, Ms Cheryl Chan, will be making a historic bid as a new candidate in a single-seat constituency.

Mr Lim would not be drawn into why he asked to leave the transport portfolio after five years, nor why his successor, Transport Minister Lui Tuck Yew, has announced that he will do the same.

Mr Lui will not be contesting the coming elections, and is leaving politics after nine years - four of those spent helming the transport portfolio. "Transport is a challenging ministry," said Mr Lim yesterday. "I think each transport minister faces his own set of challenges."

During his tenure, the issue was crowdedness on trains because of the rapid rise of the population, while for Mr Lui, it is the reliability of the train network which has come under the spotlight, he said.

"I believe that each transport minister, from Yeo Ning Hong all the way to Lui Tuck Yew, tries his level best to deal with the issues," said Mr Lim. "And in Tuck Yew's case, I'm very sure that, as he said, he gave his utmost. And I wish him all the best."

Mr Lim's strong bond with his East Coast GRC teammates was evident at the introduction session yesterday - his last public appearance with his political colleagues.

He told reporters that it has been an honour and a privilege to be an MP and minister. Mr Lim entered politics in 2001 and was made a minister of state after he was elected. He became a full minister in 2005.

"I've always believed that in life, there are causes much greater than ourselves, and that there's no greater cause than that a man be called upon to serve his country and its people," he said.

While Mr Lim spoke, East Coast GRC's anchor minister, Manpower Minister Lim Swee Say, became teary-eyed. He later said they were "tears of gratefulness to Raymond".

Earlier, Mr Lim Swee Say praised Mr Raymond Lim as a bright, sharp and serious-minded political leader, who built up a strong and committed team of activists in Fengshan.

Mr Lim Swee Say added that he had feared Mr Raymond Lim - a former Straits Times political journalist and founding member of civil society group The Roundtable - was "just another armchair critic".

"But all my doubts disappeared when he stepped forward to serve," he said.

Rachel Chang