Prime Minister Lee Hsien Loong will deliver a ministerial statement tomorrow to respond to the barrage of allegations by his siblings that he misused his power.
In doing so, he hopes to restore public confidence and dispel any doubts that have been planted by Mr Lee Hsien Yang and Dr Lee Wei Ling, who have accused him of misusing his power in a bid to prevent their late father's house at 38, Oxley Road from being demolished.
Here's a look at what's at stake and the issues that are set to dominate the session:
WHAT'S AT STAKE?
The debate in Parliament will be a crucial chance to clear the air and try to undo the damage to Singapore's reputation as one of the world's least corrupt countries, note observers.
"If the allegations are not rebutted, then it would probably call into question how the state has been running its affairs and this would ultimately be quite detrimental to Singapore's reputation in time to come," says Dr Felix Tan from SIM Global Education.
If the doubts the public may now have are not cleared, "there will be lingering thoughts about how the country has been running its organs of state".
This means the session will serve as a test for MPs as well - "whether they can ask good questions in the interest of Singaporeans, since they no longer have to speak along party lines", notes Dr Norshahril Saat, a research fellow at the ISEAS - Yusof Ishak Institute, referring to the lifting of the party whip.
Dr Tan says that if the debate is lacklustre, with MPs toeing the party line instead of making serious efforts to clarify and examine the allegations, "many Singaporeans may feel that any decision made is already a fait accompli".
Singapore Management University (SMU) law don Eugene Tan agrees. He says the debate requires People's Action Party (PAP) MPs - who make up the vast majority of Parliament - to reflect their constituents' concerns, raise legitimate questions and "dissect evidence and arguments without fear or favour".
Otherwise the debate could backfire, with damaging consequences to the ruling party.
"It boils down to what MPs make of the forum," says Associate Professor Tan. "Much is expected of them and they need to rise to the occasion."
Insight contacted over 40 PAP MPs over the week for this article. Many could not be reached or declined to comment, preferring to save their thoughts for the debate.
And while Workers' Party (WP) MPs have made public their questions relating to the Oxley dispute, they declined to comment further.
QUESTIONS ABOUT CONDUCT, 'EMOTIONS'
It all started on June 14 when Mr Lee Hsien Yang and Dr Lee Wei Ling took to Facebook to accuse their older brother of obstructing their late father's wish to demolish their family home. But there was also an allegation of serious public concern: that their brother, Prime Minister Lee Hsien Loong, had misused his power and influence to "drive his personal agenda".
As exchanges have continued on Facebook over the past two weeks, and with five ministers weighing in, it has become clear that the row over the late Mr Lee Kuan Yew's house at 38, Oxley Road, is no longer a purely family affair.
SMU's Prof Tan notes: "It has taken on the complexion of a public issue of national importance. What started ostensibly as a family dispute has transmogrified into probing concerns of governance and rule of law."
He adds that because these stinging allegations come from PM Lee's own siblings, "they have raised an element of doubt on the standing of the Prime Minister and the integrity of the Government that the opposition and critics of the Government have not been able to do".
National University of Singapore political scientist Reuben Wong says the allegations - of patronage, conflict of interest, nepotistic ambitions and abuse of power, among others - are "so serious by Singaporean standards" that the Government is forced to take them seriously and respond to the charges.
Ms Lee Bee Wah (Nee Soon GRC), meanwhile, says some of her residents have come to her with concerns over how the Government has conducted its affairs in light of the younger Lees' claims.
"These allegations are not something that should be easily brushed aside, so I have put questions about the allegations on governance issues and I believe PM Lee will be able to stand up to scrutiny," she says.
Other MPs, like Jurong GRC's Dr Tan Wu Meng, plan to take on the "emotional aspect" of the dispute, and the impact it has had on the legacy of the late Mr Lee.
"For Clementi, which is an estate with older, pioneer-generation Singaporeans, many of whom grew up with Mr Lee Kuan Yew and saw Singapore's journey, the emotion I get often is sadness - sadness that this has happened," he says. "I think they would also want to see that reflected in discussions."
THE MINISTERIAL COMMITTEE
MPs across party lines plan to question PM Lee about the committee tasked with studying options for 38, Oxley Road.
The committee has been a hot topic among Pasir Ris-Punggol GRC MP Zainal Sapari's residents, for example. It will be central in shedding light on allegations of abuse of power, he says.
He wants to know how the committee can ensure it is not being influenced by the Prime Minister. "I'd like to ask why didn't we appoint an independent panel, and what are the checks and balances that they can assure us of," says Mr Zainal.
It is a sentiment shared by Non-Constituency MP (NCMP) Leon Perera, who wants to know whether the committee will tap independent heritage experts and gauge public opinion.
His was among six questions filed by WP MPs.
He and the PAP's Ms Lee also hope for greater clarity on the committee and its terms of reference.
The two younger Lees have charged that its formation and work have been in secret and they believe it was set up to block the demolition of the 38, Oxley Road house at PM Lee's bidding.
The Prime Minister has recused himself from all government decisions relating to the house, but his siblings say he continues to have undue influence as his subordinates sit on the committee.
Deputy Prime Minister Teo Chee Hean, who set up and chairs the committee, has issued several statements on its composition and responsibilities, and will also deliver a statement on it tomorrow.
ORGANS OF STATE UNDER INFLUENCE?
Another charge is that the Prime Minister misused his position to obtain a deed of gift from the National Heritage Board (NHB) in his private capacity.
The deed concerns the donation and public exhibition of items belonging to the late Mr Lee for an NHB exhibition.
National Development Minister Lawrence Wong, who was then Minister for Culture, Community and Youth, has said PM Lee was given the deed in his official capacity.
But MPs, among them Nominated MP Chia Yong Yong and NCMP Daniel Goh, plan to scrutinise this issue further.
Associate Professor Goh wants to ask Minister for Culture, Community and Youth Grace Fu whether deeds of gifts executed with the NHB may be shared with third persons, and why the deed of gift of items from the house was released to PM Lee.
WP MP Png Eng Huat (Hougang), meanwhile, has questions about rules to prevent family members of political appointees from influencing civil servants.
This is related to items from the late Mr Lee's house which PM Lee's wife Ho Ching lent to the NHB, arranged through the Prime Minister's Office.
Another allegation made by the two siblings is that the Prime Minister was using state organs to harass them.
The influence political leaders have over state organs such as statutory boards will be a focus of Mr Chen Show Mao (Aljunied GRC).
The WP MP wants to ask what mechanisms are in place to "prevent, limit, detect and address" situations where political appointees use such bodies to obtain information, advance personal interests or "punish detractors, critics or political opponents".
CONFLICT OF INTEREST?
Law and Home Affairs Minister K. Shanmugam has also been caught up in the feud. In a Facebook post, Mr Lee Hsien Yang suggested that including Mr Shanmugam - who had advised his family on options to help achieve his father's wishes - in the ministerial committee was a conflict of interest.
Mr Shanmugam called the notion "ridiculous", noting that he had given his views to the family when he was already a Cabinet minister.
The issue of conflicts of interest will be subject to scrutiny during the debate.
WP MP Sylvia Lim (Aljunied GRC), for one, has filed a question about rules in place to ensure that political leaders who may have an interest in the subject of government decisions do not influence or take part in the process of deliberation.
She also wants to know what conflicts and potential conflicts the Government identified among Cabinet members and with regard to Attorney-General Lucien Wong on decisions relating to the late Mr Lee's assets and estates.
Dr Lee and Mr Lee Hsien Yang have pointed out that Mr Wong had been their brother's personal lawyer. He was made Singapore's Attorney-General in January.
WHAT COMES NEXT?
Parliament is not the right forum, Mr Lee Hsien Yang has declared on Facebook, adding that he has "no confidence that a fair, transparent or complete account of events will be told".
But Prof Tan says Parliament could serve as an "appropriate first forum". "Having the parliamentary debate does not preclude the convening of other forums to look into the allegations," he notes.
These options include a select committee or a committee of inquiry to delve into the matter further - though it is unlikely that these platforms will be resorted to for now, he adds.
Already, the WP's Mr Pritam Singh (Aljunied GRC) has filed a question to ask the Prime Minister whether a special Select Committee of Parliament, made up of members from all parties, can be convened.
He is suggesting that public hearings looking into allegations of abuse of power by the PM can be broadcast live.
Political analyst Derek da Cunha also notes that discussing the matter purely in Parliament carries some risk for PM Lee. If not properly and comprehensively handled, the debate can leave lingering questions.
He suggests that the fate of the Oxley Road house - which has become "a truly toxic political issue" - be taken away from the ministerial committee.
Disagreeing with the view that the house is of national significance, he argues: "It is a party political - that is to say, PAP - heritage. Many decisions were taken in the house for purely party political advantage.
"Not to decide on the fate of the house now and, instead, to defer it is also very unwise."
Even as many hope the debate will bring some resolution to an issue that has seized national attention over the past few weeks, closure may be some time in coming.
