The idea of a united opposition may make sense intuitively, but is challenging in practice because different parties have different philosophies, said Workers' Party (WP) chief Pritam Singh in a Facebook post on Wednesday.
"The reality is that different parties and individuals have different philosophies, both ideologically and in terms of how we engage the issues of the day," he wrote, sharing an article about a disagreement between Senior Minister of State for Transport Lam Pin Min and People's Power Party chief Goh Meng Seng.
On Tuesday, Mr Goh had joined a dialogue that Dr Lam was having with personal mobility device riders. Dr Lam subsequently wrote in a Facebook post that a member of an opposition party "came to politicise the issue and stoke the emotions of those present".
In his post, which sought to make a distinction between the WP's approach and that of politicians like Mr Goh, Mr Singh said the WP's objective is not the destruction of its political opponents, but "beyond the horizon - a better Singapore for all Singaporeans". Its approach reflects this, Mr Singh said.
But he pointed out that not every opposition party believes the same thing. "As a small political player in our landscape, the WP must get its political purpose right," he said. "To a large extent, this explains why opposition unity - notwithstanding friendly discussions and relationships among opposition members - remains a real challenge."
But in response to questions from The Straits Times, Mr Goh said he does not see any difficulty in opposition unity, even in this context.
"We exist in different parties precisely because we have differences - in style, in vision, in approach or even in policy matters," he said. "It is the diversity we should embrace, not resist."
Mr Goh compared the situation to a company in which people perform different roles and have different ideas. As long as the goals remain the same, "all roads lead to Rome", he said.
His views were echoed by People's Voice party chief Lim Tean, who has spoken out in favour of an opposition coalition.
Such alliances are the way forward in many political systems today, he said. "In today's society, we must have a big tent to accommodate the diverse views of the many. Alliances make politicians work together so that better solutions can be found for society as a whole."
Singapore People's Party's newly elected chief Steve Chia told ST that in order to be a credible, competent and constructive force, the party must not oppose for the sake of opposing. He stressed the importance of an "honest, constructive and harmonious approach to politics".
"While we value opposition unity, we also understand that the opposition can be united only if we share similar values, practices and have the same vision for Singapore," he added.
Dr Felix Tan, an associate lecturer at SIM Global Education, noted that the WP differs from many other opposition parties in its "very measured approach".
"It does not always necessarily need to go head-to-head (with the People's Action Party) on certain issues but rather, tries to rationalise its policies in a calm manner," he said. "I think that is what is distinctive about the WP - that it is not always antagonistic."