SINGAPORE - Speaker of Parliament Tan Chuan-Jin and Tampines GRC MP Cheng Li Hui have resigned over an extramarital affair, in the latest incident to rock the ruling People’s Action Party (PAP).

Making the announcement in a statement on Monday, Prime Minister Lee Hsien Loong said their resignations are necessary to maintain the high standards of propriety and personal conduct that the PAP has upheld all these years.

At a press conference later, PM Lee said he had learnt about the “inappropriate relationship” between Mr Tan and Ms Cheng some time after the 2020 General Election, and counselled both of them – most recently in February 2023.

But he came across recent information that “strongly suggested that the relationship had continued”.

On July 10, a video in which Mr Tan was heard muttering “****ing populist” on the microphone during the first day of debate on the President’s Address on April 17, was uploaded onto social media platform Reddit while he was away.

PM Lee said he met Mr Tan after the Speaker returned from leave.

“During our discussion, he agreed to leave immediately – both for his unparliamentary conduct as well as his inappropriate relationship with Ms Cheng, which he had told me he would break off, but he did not,” he added.

Mr Tan and Ms Cheng’s resignations come on the heels of the arrest and release on bail of Transport Minister S. Iswaran last week. The corruption probe involving Mr Iswaran is ongoing.

In his letter to PM Lee, Mr Tan said that he was resigning from the party, as Speaker and an MP for Marine Parade GRC, with immediate effect.

He said he had made a mistake in Parliament when he uttered words that were “rude and unparliamentary” in nature, adding that he had apologised publicly and to Workers’ Party MP Jamus Lim for it.

Mr Tan said the hot mic episode had added to the hurt he caused his family.

“I have let them down. We have spoken about my personal conduct before. There are areas where I have fallen short,” said Mr Tan. “I need to take responsibility for them, and help heal my family.”

He added that he had discussed the matter with his wife and agreed he must step away from politics and devote himself to his family.

Responding in a letter, PM Lee said he appreciated Mr Tan’s admission that he had fallen short in his personal conduct. He said he understood Mr Tan’s desire to “step away from politics and help heal your family”.

During the press conference, PM Lee said Mr Tan had offered to resign in February. He accepted the resignation, but had to first ensure that Mr Tan’s residents in the Kembangan-Chai Chee ward of Marine Parade GRC continued to be taken care of.

However, when he learnt that the affair had continued, he decided “Mr Tan had to go forthwith, whether or not the arrangements were ready”. “It could not wait any longer.”

Minister for Culture, Community and Youth Edwin Tong will take care of Mr Tan’s ward, PM Lee said, adding that he would nominate a new Speaker when Parliament sits on Aug 1, and make a ministerial statement.

In her resignation letter, Ms Cheng said: “I am very sorry to be resigning in these circumstances, and would like to apologise to the party, as well as to my residents and volunteers.”

Minister for Social and Family Development Masagos Zulkifli will stand in for Ms Cheng in Tampines East.

PM Lee said: “It is painful to do this to our friends and comrades-in-arms, and it can also be politically embarrassing and costly. But the PAP has to maintain party discipline and standard of conduct. Our duty is to Parliament and the people of Singapore, and that is paramount.

“It is simply inappropriate to have the Speaker having a relationship with one of the MPs. It is not appropriate; it is not acceptable.”

In his letter, Mr Tan said the hot mic incident – which came to light after the video titled “SG Speaker of Parliament Tan Chuan-Jin insults Jamus Lim: ‘****ing Populist’” was uploaded to Reddit – had raised broader questions over his neutrality and impartiality as Speaker.

Mr Tan had been reacting to a speech by Associate Professor Lim on doing more to help lower-income Singaporeans. 

“Deservedly, there has been much disquiet over my remarks. Many felt that I was not impartial,” wrote Mr Tan. 

He added that others also felt it was “conduct unbecoming” of a Speaker of Parliament, and some have called for his resignation.

When such mistakes happen, Mr Tan said, all MPs, himself included, will have to apologise and withdraw their comments. 

However, as the Speaker, he “should have known better” and held himself to a higher standard, he said, adding that the credibility of Parliament and the chair is critical and cannot be compromised.

Mr Tan was elected as an MP for Marine Parade GRC in 2011, and became the 10th Speaker of Parliament on Sept 11, 2017. He was previously minister for social and family development and minister for manpower.

Ms Cheng made her political debut in the 2015 General Election in Tampines GRC.

Both of them have deleted their social media accounts.

Before this, then Speaker of Parliament Michael Palmer resigned in 2012 after admitting to an extramarital affair with a staff member of the People’s Association who had been working in Pasir Ris-Punggol GRC.

PAP MP David Ong resigned in 2016 after reportedly having an extramarital affair with a woman who was a grassroots activist in his Bukit Batok single seat ward.