Going by changes in population and housing developments, at least six constituencies face having their boundaries redrawn.
The Single-Member Constituency of Sengkang West has grown so much since 2011 that it now exceeds the last electoral boundaries committee's prescribed ratio of 20,000 to 36,000 voters per MP.
Its voter numbers swelled by 47 per cent from 26,882 in 2011 to 39,586 in the Elections Depart-ment's last count.
Small wonder, given that at least 15 Build-To-Order housing developments - or about 10,500 flats - have been completed in the ward since the last general election.
Its MP Lam Pin Min says: "As the population in Sengkang West has almost doubled since the last election, it is unlikely for Sengkang West to remain as it is. We are therefore expecting some changes to the electoral boundary."
ANYTHING CAN HAPPEN
I'm not sure which side I'll be pulled to, since my ward is in the centre of all these (population) changes.
DR LIM WEE KIAK, a Nee Soon GRC MP
Another four constituencies are close to busting the prescribed population-ratio cap: Pasir Ris-Punggol and Nee Soon GRCs, and the single-seat constituencies of Punggol East and Bukit Panjang.
1. GROWING POPULATION
Six constituencies have swelled as more voters have moved in since GE2011 and so they may be redrawn.
• They are the single-seat constituencies of Bukit Panjang, Punggol East and Sengkang West; as well as Nee Soon, Pasir Ris-Punggol and Sembawang GRCs.
• A new Sengkang-Punggol GRC could be formed from parts of Sengkang West and Pasir Ris-Punggol GRC.
• So too could a new Woodlands GRC from parts of Nee Soon GRC and Sembawang GRC.
• A new constituency in the west could be drawn from parts of Holland-Bukit Timah GRC - possibly Zhenghua ward - and the Bukit Panjang single-seat constituency.
2. POTONG PASIR & JOO CHIAT
Single-seat Potong Pasir and Joo Chiat, which saw close contests in GE2011, are likely to be redrawn.
• Both constituencies are electoral anomalies: Potong Pasir has too few voters, and Joo Chiat is made up entirely of private housing.
• Potong Pasir could be absorbed by Bishan-Toa Payoh GRC, and a part of this larger GRC could be made a new single-seat constituency.
• Joo Chiat could be absorbed by Marine Parade GRC.
3. FOUR- & FIVE-MAN GRCS
Several four- and five-member GRCs could be rejigged, leading to more four-member GRCs .
• The Kreta Ayer-Kim Seng ward of Tanjong Pagar GRC may be combined with parts of Moulmein-Kallang GRC to form a new Kallang GRC.
• Marine Parade GRC and Chua Chu Kang GRC may also see boundary changes .
4. ALJUNIED GRC
• The boundaries of Aljunied GRC and Hougang will most probably be left intact.
• But single-seat Punggol East may see changes as its population has grown.
Pasir Ris-Punggol GRC, which lies immediately to the east of Sengkang West, is the next largest in growth. It has increased by more than a fifth - or 38,000 voters - since the last election. Its 206,913 voters now puts it at about 34,485 voters for each of its six MPs, close to the upper limit of 36,000.
Most of this expansion is concentrated in Ms Penny Low's Punggol North ward, and Dr Janil Puthucheary's Punggol West ward.
It is very likely that part of Pasir Ris-Punggol GRC will be hived off, given Prime Minister Lee Hsien Loong's directive to the electoral boundaries review committee to lower the average size of GRCs to fewer than five MPs.
A plausible scenario is for the hived-off portion to merge with Sengkang West, or part of it, to form a new Sengkang-Punggol GRC. The profiles of residents in both areas are similar, being largely young, lower- to middle-income families in Housing Board homes.
Punggol East, however, is a less clear-cut situation. Although its 34,398 voters put it near the upper limit of voters per MP, it is helmed by Ms Lee Li Lian of the Workers' Party. There is a general expectation that the boundaries of opposition-held constituencies will not be redrawn. But the question of whether this continues - or if parts of Punggol East are absorbed into a new GRC - is up in the air.
Nee Soon GRC is another area which has grown - 10 per cent in terms of voters - since 2011. This is mostly due to new housing projects springing up in Ms Lee Bee Wah's Nee Soon South ward. "Overall, housing units are up, so we think there will be some form of boundary changes," says fellow Nee Soon GRC MP Lim Wee Kiak.
But if a change does come, there is a high chance that it may be in the outlying ward of Canberra, where he serves. "Geographically, Canberra is not within the Nee Soon HDB township but lies more in Sembawang," says Dr Lim.
The buzz is that the ward could be hived off, possibly as a single-seat constituency.
Alternatively, it could join a new Woodlands GRC - which can be formed by drawing on parts from its northern neighbour, Semba-wang GRC. These may include parts of National Development Minister Khaw Boon Wan's Sembawang ward and Ms Ellen Lee's Woodlands ward, which had an influx of 3,200 new flats over the last five years.
Says Dr Lim, with a laugh: "I'm not sure which side I'll be pulled to, since my ward is in the centre of all these (population) changes."
As for Bukit Panjang, the single-seat constituency, held by North West District Mayor Teo Ho Pin, now has 34,294 voters, another constituency near the upper limit.
Meanwhile, about 4,400 flats have been added to Zhenghua - a ward in the Holland-Bukit Timah GRC and served by Mr Liang Eng Hwa. The committee may well do some rejigging of the boundaries there as well.