As the mid-point of its five-year term approaches, the ruling People's Action Party (PAP) has identified about 200 potential candidates for the next general election, The Sunday Times has learnt.

Some names floated at this early stage are: Mr Charles Lim, 41, general counsel at the sovereign wealth fund GIC; Mr Alvin Tan, 37, head of public policy (South-east Asia), at social media giant Facebook; and Ms Jaclyn Seow, 32, who works in strategic projects at Raffles Medical Group.

Others include those who spoke at the PAP convention two weeks ago: Ms Fang Eu-Lin, 39, a partner at consultancy PricewaterhouseCoopers and daughter of former Nominated MP Fang Ai Lian; Mr Jagathishwaran Rajo, 30, an NTUC industrial relations officer; and Ms Asyifah Rashid, 27, an A*Star biomedical research administrator.

The list - which consists of people from the private and public sectors - is still growing. Some were first considered for the 2015 General Election.

Around a quarter of the 200 have begun attending tea sessions with ministers, which party insiders said began in earnest earlier this year. These sessions help party leaders assess them, and are part of a long process before they are whittled down to the final slate. The PAP replaces about a quarter of its slate for every general election - with 26 new faces in 2006, and 24 each in 2011 and 2015.

PAP organising secretary Gan Kim Yong, who is overseeing the selection process, told ST that names are suggested by MPs, party activists and supporters.

"It's an ongoing process that spreads over the entire period from GE to GE," said the Health Minister, who also oversaw the process for the 2015 General Election.

The next general election is due by April 2021. Mr Gan is assisted by Mr Heng Swee Keat, who is Finance Minister, and Ms Sim Ann, who is Senior Minister of State for Trade and Industry and Culture, Community and Youth.

The search this round comes as the ruling party is forming the core of its fourth-generation leadership.

While Prime Minister Lee Hsien Loong - who has said he intends to step down by 2022 - has indicated the fourth PM is likely to be in the current Cabinet, PAP MPs said new candidates at the next general election could still form part of the fourth-generation leadership.

In the current Cabinet, just six of the 21 ministers are younger politicians who entered politics in 2011 and 2015. In addition, one who entered in 2006 - Minister in the Prime Minister's Office Josephine Teo, 49 - is seen as a fourth-generation leader.

Pasir Ris-Punggol GRC MP Zainal Sapari said: "We need people to be ministers, political office holders, as well as people who can connect on the ground."

A PAP MP, who asked not to be named, added: "There are always leadership opportunities for some in the next batch. Now is the time to look out for new layers of leadership as well."

In the initial phase of the selection process, groups of potential candidates attend tea sessions hosted by a minister and a few MPs.

In the later stages, they are interviewed individually by panels of ministers. ST understands that the panel stage has not begun.

In the past, candidates have also been asked to undergo psychological profiling.

Closer to the election, they will typically be attached to MPs to do constituency work, if they were not party activists previously.

Tampines GRC MP Baey Yam Keng said that compared with 2006, when he was a new candidate, the party now asks hopefuls to get involved on the ground earlier.

This avoids last-minute introductions, which can trigger rumblings among party rank and file about candidates being parachuted in.

Public servants, though, are usually sent in only in the final months leading up to an election - after they have resigned from public service.

Mr Tan has been a volunteer at Kreta Ayer-Kim Seng since 2005, while Ms Fang is now helping out at Bukit Timah.

Mr Lim is not yet at any PAP branch, but has been a district councillor at the Central Community Development Council for the past decade.

All declined comment.

But the task of recruiting potential candidates is more difficult this time round, said several MPs. Those who declined cited reasons such as a more difficult electorate and rising vitriol on social media.

Pasir Ris-Punggol GRC MP Teo Ser Luck added that some of those he approached are concerned about the political climate for PAP MPs becoming tougher over the years.

A veteran party activist who did not want to be named also cited "nastier attacks" on social media.

But some who said "no" when approached can still be persuaded to hold off on deciding, said the MPs.

Marine Parade GRC MP Seah Kian Peng said he coaxes people to keep an open mind and to attend tea sessions first, adding: "I tell them that it's a journey where there is a bit of self-discovery for the individual, while at the same time the party is assessing you."