Losing candidates from the opposition Workers' Party (WP) have struck a positive tone despite suffering surprise and heavy defeats, saying they would continue working the battlegrounds and promising to come back stronger at the next polls.

"(This) is the way the WP has always functioned. We will like to come back to the places where we have contested in and we won't quit," said Mr Yee Jenn Jong, 50, whose five-member team lost to the PAP with 35.93 per cent of the vote.

But whether he will continue to lead the effort depends on the party's leadership, he said.

"The question is, would it be me? It really depends on what plans the party has and also how many more years I think I can carry on."

Mr Yee spoke to reporters yesterday as the WP members made their way around their respective constituencies to thank residents.

At another thank-you parade in the Punggol East Single-Member Constituency (SMC), former WP MP Lee Li Lian said she would contest there again, given the chance.

"With the party's support, if Punggol East is still around... From experience, I think it might not be," said Ms Lee, 37, referring to the possibility of the SMC disappearing from the electoral map at the next polls through boundary changes.

She won the seat in the 2013 by-election, but lost on Friday to PAP challenger Charles Chong, with a vote share of 48.24 per cent.

The WP has retained six seats in Parliament - five in Aljunied GRC and one in Hougang SMC. The results had shown a significant swing in favour of the PAP that surprised analysts.

When asked if the WP was disappointed with its results, Ms Lee, who appeared subdued as she greeted residents and received hugs from some of them, said: "Perhaps (we are) disappointed. But we will come back stronger. We have done it before and we will do it again."

She also said she had decided not to run for the Non-Constituency MP role even before she reached the WP assembly centre at Hougang Stadium after the results were announced on Friday night, as she thought there were other candidates, such as those fielded in Fengshan SMC and East Coast GRC, who are more deserving of the role.

Candidates from the party's East Coast GRC team, which lost to the PAP with a vote share of 39.27 per cent, and Fengshan SMC, which lost with a vote share of 42.48 per cent, also made their rounds in their respective constituencies yesterday.

They did not speak to reporters, but National University of Singapore sociologist Daniel Goh, a member of the East Coast GRC team, put a positive spin to the party's loss in a Facebook post later yesterday.

The 42-year-old said: "My work is to continue this national service to build up the WP as a credible choice and voice to keep the iron in Singapore's veins."

•Additional reporting by Tham Yuen-C