An opposition party in Singapore has mounted the first legal challenge against an online misinformation law that activists say is being used to silence criticism of the government ahead of elections.

The Protection from Online Falsehoods and Manipulation Act (POFMA) came into force in October and gives the government the power to order corrections be placed next to posts it decides are false.

Since the law came into force in October, several opposition figures and activists have been ordered to place a banner next to their online posts stating that they contain false information.

The Singapore Democratic Party (SDP), one of a handful of small opposition groups, has now asked the courts to overturn a government order for it to correct two Facebook posts and an article on its website.

The Facebook posts said many Singaporeans had been displaced from white-collar jobs by foreigners -claims the government said were "false and misleading".

"We undertake this legal action because, as difficult as it may be, we must stand up for our fellow Singaporeans and fight for what little space we have left in Singapore to uphold our democratic freedoms," the party said on its website late on Wednesday.

Challenge next Thursday

The challenge was filed against Manpower Minister Josephine Teo, whose ministry last month ordered the corrections be put up and later rejected an application to withdraw the order.

"Ms Teo has plunged a dagger into the heart (of) Singapore's political system already plagued by anti-democratic rules that keep the (ruling People's Action Party) entrenched in power," said the SDP, which currently has no seats in parliament.

While it is praised for its economic management, Singapore's government is also regularly criticised for curbing civil liberties in the city-state of five million people. The country is ranked 151 of 180 in RSF's World Press Freedom Index.

The People's Action Party (PAP) has ruled Singapore for decades and is expected to comfortably win polls that are likely to take place within months. The weak opposition is able to offer little real challenge.

The High Court has set Thursday next week to hear the SDP's challenge.

The government insists the legislation is necessary to prevent the circulation of misinformation that could sow divisions in the multiethnic, multifaith country and has said the law will not be applied to opinions, satire, criticism or parody.

Neighbouring Malaysia last year scrapped a controversial fake news law that had been introduced by the last government weeks before an election that saw it lose power for the first time.