SINGAPORE - Madam Halimah Yacob has resigned as Speaker of Parliament and MP for Marsiling-Yew Tee GRC MP to stand in next month's presidential election.

She submitted her letter of resignation to Prime Minister Lee Hsien Loong on Monday (Aug 7), informing him of her decision to step down as MP and leave the People's Action Party (PAP), where she was a member of the central executive committee and chaired the PAP Seniors' Group.

The 62-year-old also sent a resignation letter to the Clerk of Parliament, and another letter to Deputy Speaker Charles Chong, asking him to lead the House until a new Speaker is elected.

Madam Halimah announced her decision to run for the highest office in the land on Sunday.

In her letter to PM Lee, who is secretary-general of the PAP, Madam Halimah said she decided to contest the presidential election after careful consideration and consulting friends, colleagues and family members. "They have given me their strong support and I am also very encouraged by the many Singaporeans who had asked me to put myself up as a candidate."

She said that she would miss her residents, her constituency work in Marsiling and her role as Speaker.

"In running for the office of the Elected President, my passion and desire to serve the people continues," she added. "It is a heavy responsibility but I hope that with the support of young Singaporeans, we can do more good together."

She noted that she started her career with the National Trades Union Congress (NTUC) after graduating in 1978, and served for 30 years in various roles including as Deputy Secretary-General and Director of Legal Services, where she fought for workers' rights.

"I am proud to say that my colleagues and I worked tirelessly to get the best results for our workers. I fully understood their concerns and shared their joys, and I am honoured that I was able to contribute to their continued well-being," she said.

The experiences and insights she gained with the labour movement were invaluable, and it became not just a job, but a calling, she added.

She said her time at NTUC has strengthened her passion and interest to contribute to society and serve Singaporeans. It also taught her the importance of building trust, which also applies in politics.

"We need to secure the confidence of the people we serve. If they trust us, they will understand that we are not there for personal reasons," she said.

She recalled when then-Prime Minister Goh Chok Tong asked her to stand in the 2001 general election. Although she felt she was already contributing to public service through NTUC, he persuaded her that she could play a bigger role as an MP.

In 2011, she was appointed Minister of State for the former Ministry of Community, Youth and Sports.She said she was grateful for the opportunity to serve more Singaporeans through that role, particularly the most disadvantaged and vulnerable.

When she became Speaker, she said she had the honour of presiding over sittings in Parliament and giving all MPs equal opportunities to speak, regardless of party affiliations.

She recounted leading a parliamentary delegation to Mexico, where she addressed their senate.

"The standing ovation that I received was acknowledgement of what Singapore stands for - incorruptibility, meritocracy, multi-racialism, racial harmony and our technical, business and educational achievements. It was a moment of great pride for me as a Singaporean," she said.

The opportunities she had were made possible because Singapore is "a multi-racial, meritocratic nation, where everyone regardless of race, language or religion, can chase their rainbows", she added.

"It is with all these in mind that I have made the decision to offer myself as a candidate for the elected presidency," she told PM Lee.

Her resignation leaves vacant the post of Speaker and her seat in Marsiling-Yew Tee GRC.

Madam Halimah asked PM Lee to quickly appoint replacements to avoid any disruption.

There is no requirement under the law to call a by-election if an MP resigns. On Sunday, National Development Minister Lawrence Wong said he and the other MPs in the GRC - Mr Alex Yam and Mr Ong Teng Koon - will fill in to serve residents in her ward.

Madam Halimah also thanked PM Lee, fellow MPs and party members for their support and friendship.

She said: "I look forward to continuing the good work together in the years ahead."