KUALA LUMPUR - Just 10 months in office, Malaysia's ruling coalition Pakatan Harapan (PH) is contesting its seventh by-election.

On Saturday (March 30), nomination for the state seat of Rantau in Negeri Sembilan saw four candidates filing their names as contenders.

Umno's acting president and former Negeri Sembilan menteri besar Mohamad Hasan, 62, is contesting again, after having the election court nullify his victory in last May's election.

Datuk Seri Mohamad - affectionately known as Tok Mat - won uncontested the seat that he held for three terms after Parti Keadilan Rakyat's (PKR) candidate, Dr Streram Sinnansamy, was denied entry to the nomination centre last year for not having an Election Commission pass.

PKR is again fielding Dr Streram, 60, for the by-election.

The remaining two candidates are independents - Mohd Nor Yassin and Malar Rajaram.

Supporters from Barisan Nasional and PH turned up in droves, with riot police on standby as the crowd riled opposing sides with shouts across the police barricade.

The by-election is closely watched as Mr Mohamad, who has the Malay votes in his pocket, would need to court the non-Malays who make up 45 per cent of the electorate.

Some 26 per cent of the 29,926 registered voters in Rantau are Indians, a vote bank that PKR is banking on by fielding Dr Streram, an anesthesiologist from Klang, Selangor.

PH, after having lost two consecutive by-elections this year, has more to lose given its inability to wrestle the Malay vote from the joint forces of Umno and its current ally, Parti Islam SeMalaysia (PAS). It failed to win the Cameron Highlands ward in January and lost the Semenyih state seat earlier this month.

Mr Mohamad, who is well-known among locals, has an edge over his opponents due to his untarnished image - a rare gem among the Umno leadership caught in chains of corruption probes by the new administration. He became Umno acting president in December after Ahmad Zahid Hamidi went on leave following his mounting court charges.

A win for Mr Mohamad would strengthen his leadership within Umno and Barisan Nasional.

Polling day is on April 13 while early voting is on April 9.