SINGAPORE - There are people with big egos who join the Progress Singapore Party (PSP) for personal gain, instead of contributing to the nation's development, said its secretary-general Tan Cheng Bock on Thursday (May 21).

Addressing the recent series of departures from the party, Dr Tan said certain members went beyond the limits the party had allowed for them to air their disappointments and dissatisfaction.

"We give everybody a chance. But sometimes, they got very big egos. And when you got big egos, it is very difficult. When their egos get hurt, they react very negatively," he said during the party's virtual outreach session on Facebook.

"Those people who come in to join the PSP hoping to extract something from the party for themselves, I think even if they leave, I will not feel sorry."

It is the PSP chief's first public statement on the resignations and expulsions from the party in the past three months.

At least five have left. Among them are vice-chairman Michelle Lee, who resigned in March, about six weeks after she took up the post, citing family commitments; and member Jan Chan, a technology consultant who was expelled in the same month for an offensive Facebook post that mocked the Bible and the Quran.

Another member who was expelled is Daniel Teo, who works in a marine infrastructure company. He was told to go at the start of May for making an anonymous video claiming the party had been infiltrated and funded by foreign sources.

On May 12, member Ravi Philemon, who was believed to be the party's intended candidate for Hong Kah North, resigned. He was said to be unhappy with the party's handling of the video incident.

Dr Tan said that in the beginning, party membership was open to people from all walks of life.

"Now, over time, we realise that some joined the party expecting what the party can do for them," he said. "There are people who believe that their way of doing things should be the only correct way, and they think we should comply to their way of doing things."

He also said the party has more than 1,000 members, and having between 20 and 30 people resigning is "no big deal".

The outreach session was held live on Facebook, but targeted specifically at residents living in the western part of Singapore. It had a panel of nine people, with a mix of the party's central executive committee members and ordinary members.

"My link with the west is as a Member of Parliament for 26 years in the constituency of Ayer Rajah," said the 80-year-old, who was a longtime member of the ruling People's Action Party. "I was elected six times in six general elections, and I did fairly well in Ayer Rajah constituency."

He added that he also looked after the surrounding constituencies in his roles as chairman of Jurong East Town Council, then the Bukit Timah Community Development Council and later West Coast-Ayer Rajah Town Council.

The Straits Times had reported in March that Dr Tan will likely contest in West Coast GRC, as the PSP sets its sights on seven SMCs and eight GRCs at the next general election which must be held by April next year.

Responding to a question on the state of cooperation among opposition parties ahead of the election, PSP's assistant secretary-general Leong Mun Wai said: "So far, we have a very cordial relationship, and I think the likelihood of a three-cornered fight in a GRC is quite minimal. There has been a lot of progress in the coordination among the opposition parties."

Mr Leong said the opposition, in working together, hopes to secure one-third - or 32 - of the seats in the election.