SINGAPORE, July 18 — The resignations of Speaker of Parliament Tan Chuan-Jin and Member of Parliament (MP) Cheng Li Hui are the latest in a series of controversies and while these things happen "from time to time”, the People’s Action Party (PAP) has to make sure that they are dealt with "rigorously as well as transparently”, said Prime Minister Lee Hsien Loong yesterday.

"Everybody should draw the right conclusions and do the right things, whether they are in the Government, whether they are in the party or the public watching how we are dealing with it,” he said, in response to a question about a perceived slip in PAP’s standards during a briefing with news editors at the Istana following the resignations of Tan and Cheng.

Tan, MP for Marine Parade Group Representation Constituency (GRC), and Cheng, the Tampines GRC MP, had continued to be involved in an "inappropriate relationship”, despite Lee urging them to stop in February. They have since resigned from Parliament and from the party.

"In the case of Tan Chuan-Jin and Cheng Li Hui, they did not live up to the standards which were expected. We tried to get them to mend their ways, it did not work, and they had to go,” he added.

The latest case comes after a string of high-profile controversies in recent weeks involving MPs from the ruling party.

Last week, Transport Minister S Iswaran was arrested by the Corrupt Practices Investigation Bureau (CPIB) in relation to a graft probe.

The arrest led Deputy Prime Minister Lawrence Wong to state that the PAP will be upfront and transparent even when such developments are "potentially embarrassing or damaging” to the party or the Government.

Earlier this month, Parliament also debated the rental of bungalows along Ridout Road by Law and Home Affairs Minister K Shanmugam and Foreign Affairs Minister Vivian Balakrishnan. Investigations by CPIB and a separate review conducted by Senior Minister Teo Chee Hean on the matter found no wrongdoing by the ministers involved.