Workers' Party (WP) Non-Constituency MP Dennis Tan has been tipped to be his party's candidate in its Hougang stronghold in the coming election.

Party sources say Mr Tan is set to take over from two-term WP MP Png Eng Huat.

Mr Tan, 50, has been a familiar face in the single-member constituency (SMC), where he has been shadowing Mr Png for the past few years.

The shipping lawyer, who debuted as a WP candidate in the 2015 General Election, is said to have been assisting Mr Png at Meet-the-People Sessions, and is also a regular at constituency events, temple dinners, as well as tea sessions with residents, sparking speculation that he may be fielded in Hougang.

He is also often seen in pictures posted on WP's Hougang SMC Facebook page, another indication that he is being groomed for the constituency.

Some residents in the area who spoke to The Straits Times referred to him as Mr Png's right-hand man.

Minimart owner Helen Tan, 53, described Mr Tan as friendly and said he is "always walking around with Mr Png". But she added that when asked, he did not say if he would be standing in the constituency.

It is unclear if Mr Png, 58, would be fielded in a different constituency or retire from politics. Both Mr Tan and Mr Png declined to comment when asked who WP will field in the constituency.

Hougang voters have voted into Parliament a candidate from the WP in all six elections since 1991, the year that former party chief Low Thia Khiang wrested control of the constituency from the People's Action Party with 52.82 per cent of votes. Mr Low, who left the SMC to lead a team in neighbouring Aljunied GRC in 2011, is said to remain influential in Hougang, and still attends New Year dinners and other constituency events there.

In the past, he has introduced the party's potential candidates there to residents, and had taken Mr Png and Mr Yaw Shin Leong - who was Hougang MP from May 2011 to February 2012 - around the estates. If fielded in Hougang, Mr Tan would be the third WP candidate to contest the constituency after Mr Low's departure.

Mr Tan's ability to converse in Teochew, which Mr Low often uses in election rally speeches, would be a factor in his candidacy in Hougang, said party sources.

He was also identified as one of the party's future leaders by Mr Low during the 2015 GE. That year, Mr Tan stood in Fengshan SMC, where he got 42.5 per cent of the votes, losing to the PAP's Ms Cheryl Chan. As one of the best-performing losers in that election, he got a seat as a Non-Constituency MP.