Malaysia's Election Commission says it has fixed May 9 for general elections, that could determine scandal-plagued Prime Minister Najib Razak's political survival.

Analysts say the move to hold the vote on a working day may reduce voter turnout that could disadvantage the opposition led by former strongman Mahathir Mohamad, Asia's longest serving leader for 22 years before he retired in 2003.

The Election Commission also set an 11-day campaigning period, which was shorter than the 15 days in 2013 polls. It said Tuesday that 14.968 million voters will cast their ballot, an increase of 1.7 million new voters from 2013.

Najib, 64, is seeking a third term in office and under pressure to improve his National Front coalition's performance after support eroded in the last two elections.