Malaysian Prime Minister Najib Razak on Monday pledged to review the country's tough sedition law that critics say has been used to silence dissent as part of reforms to claw back votes.

Parliament was also expected to pass a new law to replace the controversial Internal Security Act (ISA) that allowed for indefinite detention without trial of terror suspects and dissidents.

The slew of reforms follows Najib's pledge last September to improve civil liberties in a country long known for authoritarian rule ahead of elections expected to be called soon.

"The government will continue to carry out these political reforms. As such, I would like to announce that the government will comprehensively review the Sedition Act," he said in an address to lawmakers.

However, Najib said the new law replacing the Sedition Act, which has been used against political opponents, would still be used against those who "bring hatred or insult" to the country's monarchy and "promote feelings of ill-will and hostility between races or classes" in multi-ethnic Malaysia.

He did not say when the new act would be tabled or give further details.

Najib said the government would also replace the restrictive Printing Presses and Publications Act that requires all publications to be licensed annually, with a media council that will help self-regulate the industry.

"We want to create a Malaysia where human rights principles are upheld, where an individual is free to gather peacefully and to express opinions openly while balancing the interests of the individual and community," Najib added.

Later Monday, parliament, where Najib's coalition holds well over half of all seats, is expected to pass the Security Offences (Special Measures) Act to replace the colonial-era ISA, which was heavily criticised by rights groups.

The new act, tabled in parliament last week, stipulates suspects must be released or brought to court after 28 days in custody, and people cannot be detained for their political beliefs.

The premier has been courting voters ahead of polls, which could take place within months and will likely be a tight battle against a resurgent opposition.

Critics have slammed Najib's reform pledges as ploys to garner voter support after the ruling Barisan Nasional coalition suffered its worst performance ever at the last polls in 2008.