Kuala Lumpur  - Thousands of voters were expected to turn out Tuesday for a by-election pitting Malaysia's ruling party against an Islamic opposition group.

Voters started trickling into polling stations in the rural Manek Urai constituency to choose a representative for the Kelantan state legislature, but election commission officials have said more than 12,000 people are expected to cast their votes.

The Manek Urai seat, a stronghold of the opposition Parti Islam SeMalaysia (PAS), which has ruled Kelantan since 1990, fell vacant when its representative died of a heart attack in May.

The polls will be largely seen as a test of support among ethnic Malay voters - who make up the majority of the Manek Urai constituency - for new Prime Minister Najib Razak.

Najib, who celebrated 100 days in office on Saturday, succeeded former premier Abdullah Ahmad Badawi, who lead the powerful ruling National Front coalition to its worst-ever losses in last year's March general elections.

The opposition alliance, made up of PAS and two other parties, denied the Front a two-thirds majority in Parliament and grabbed control of five out of the country's 13 states.

Analysts say the ruling front suffered its lowest ever level of public support due to allegations of rampant corruption and racial discrimination. (dpa)