PSM's unilateral move to contest in seats currently held by Pakatan Harapan component parties will invite reciprocal action, Perak DAP chief Nga Kor Ming said today.

Nga said Perak Harapan will field a candidate in Sungai Siput, PSM's only seat in any legislative body.

"In view of PSM's unilateral decision to contest in DAP-held seats, Harapan will contest in Sungai Siput.

"This is to allow the wise Sungai Siput voters to choose a coalition capable of replacing Umno and BN," Nga said in a statement.

PSM's Dr Michael Jeyakumar Devaraj won the Sungai Siput seat in 2008, on a PKR ticket, and retained the seat in 2013.

In both elections, PSM did form an electoral pact of sorts with DAP and PKR. However, PSM has vowed to go alone into the forthcoming general election.

The party has announced candidates for Seri Muda in Selangor and two state seats in Perak.

Despite their reputation as a mosquito party, PSM has proven that it is capable of souring the chances of more established political parties.

In 2013 for instance, PSM's then secretary-general S Arutchelvan garnered 15 percent of the votes in Semenyih, while PKR's Hamidi A Hassan obtained 36 percent of the votes.

Combined, the two opposition candidates had more votes than the BN candidate, who eventually won.