Where Singapore's Voting Lines Keep Moving

But that's not to say that there's no pattern. The mapping exercise surfaced another finding, that the most frequent changes are not in opposition strongholds, but in the constituencies around them – places where the Workers' Party (WP), Singapore’s most electorally successful opposition party, has tried to break in.

These appear to be Singapore’s most politically fluid zones: not the safest seats, but the shifting edges.

If boundary changes were meant to weaken opposition support in the strictest sense of the word, WP strongholds should be the hottest zones for redrawing. But they are cold: the single-seat ward of Hougang, which the party held since 1991, and Aljunied Group Representation Constituency (GRC), which it wrest from the PAP in 2011, barely shifted over two decades and are among the least changed constituencies in Singapore.

Instead, the churn concentrates around them. The most frequently redrawn areas sit on the edges of these strongholds, in places such as Sengkang and East Coast where the WP has either broken through or mounted strong challenges.

On average, WP-contested constituencies experienced more boundary churn. In the four redrawing exercises between 2006 and 2025, 35.8 per cent of the territory contested by the party was reassigned to a different constituency after each election. For seats the party did not contest, the figure was lower, at 21.7 per cent.

A breakdown of this boundary churn across the election cycles was also revealing. Every boundary redrawing since 2006 has consistently churned more land in WP-contested seats than elsewhere, with gaps ranging from about 2 per cent in 2011 to nearly fivefold in 2020.

To critics, these are not isolated cases but part of a pattern — constituencies become harder to contest just as opposition support builds. What the data cannot settle is intent.

Singapore Management University law professor Eugene Tan said the findings stop short of proving gerrymandering, but raise questions. “They suggest that boundary redrawing can do with more clarity, even as the exercise is neither a science nor an art,” said the former Nominated Member of Parliament (NMP).

Geography may partly explain the pattern, he added. “The Workers’ Party contests in the eastern half of the island. So if there is more churn involving WP-contested wards, it is to be expected,” he said. “With new towns in the western half developing, the non-WP churn will likely increase unless the WP decides to wade into contests in this part of the island.”

Associate Professor Walter Theseira of the Singapore University of Social Sciences, also a former NMP, suggested a stronger test: whether opposition-contested constituencies are redrawn more often than others experiencing similar population changes. If population change is indeed the driver, similar shifts should not more often trigger boundary changes in opposition-contested areas, especially where margins are close, he said.

During the 2024 Parliament debate on the fairness of the boundary-drawing process, Minister Chan Chun Sing pushed back at gerrymandering accusations, arguing the premise does not fit Singapore. The Electoral Boundaries Review Committee (EBRC), he said, “does not have access to voting information” and “does not consult the PAP or any other political party.” Its members are senior civil servants, and “party politics do not come into this exercise.”

More fundamentally, he argued, Singapore lacks the conditions that make gerrymandering effective elsewhere. “Every electoral division is more or less a microcosm of our nation,” he said, pointing to the absence of fixed political or demographic enclaves. About 200,000 voters change their residential address each year, in a population of roughly 2.7 million electors. Add new voters entering the roll each cycle, and this “calls into question any suggestion of the efficacy of attempts at gerrymandering.” Boundary changes, he said, are driven by population shifts and practical considerations rather than past election results.

Boundary changes may be purely administrative, as the Government maintains. Or they may produce political effects, intended or otherwise, as critics argue. The maps cannot distinguish between the two. What they do show is how uneven the experience is.