The Singapore Democratic Party (SDP) has filed a lawsuit in the High Court to get the Govern- ment to call a by-election in Marsiling-Yew Tee GRC.

A seat in the four-member constituency lies empty as former MP Halimah Yacob had resigned to run in the presidential election, which she won yesterday.

Her three former colleagues from the People's Action Party have said they will collectively take care of the residents in her former ward of Marsiling.

Mr Zaqy Mohamad, an MP from neighbouring Choa Chu Kang GRC, has been tasked to help grassroots organisations in Marsiling.

Yesterday, the SDP said the PAP's decision not to call a by-election when a seat is vacated in a GRC is wrong. It cited Section Article 49 (1) of the Constitution, which states: "Whenever the seat of a Member, not being a non-constituency Member, has become vacant for any reason other than a dissolution of Parliament, the vacancy shall be filled by election in the manner provided by or under any law relating to Parliamentary elections for the time being in force."

It pointed out that the PAP-led Government had introduced the GRC scheme, which "mandated that each GRC include at least one candidate from a predetermined minority race". "But the same party is also the one who has arbitrarily decided that if that minority member resigns, there is no need to replace him or her in a by-election," the SDP said in a statement.

"Even though it won the last election and forms the Government, it cannot and must not be allowed to do as it pleases without any check from the opposition," it added.

A pre-trial conference is set for Oct 9. The party engaged law firm Peter Low & Choo, and urged Singaporeans to contribute to the legal expenses.

The topic of whether a by-election is mandatory came up on Feb 6 when Parliament debated changes to the Presidential Elections Act.

Workers' Party MP Pritam Singh had asked what would happen if a minority member of a GRC stepped down to run for president.

Minister in the Prime Minister's Office Chan Chun Sing said a by-election need not be called if a GRC MP resigns or is incapacitated in any way.The reason is the GRC scheme is meant to achieve two purposes: Ensure there are enough minority members in the House and ensure no political campaigning is done on issues of race and religion.

These goals would not be affected if one member of the GRC left, Mr Chan added.