Religious groups in Singapore could be held responsible for hiring or inviting foreign speakers who incite religious tensions.

Observers told The Straits Times this is one possible change to the Maintenance of Religious Harmony Act (MRHA), which is currently being reviewed by the Government.

Another possibility is that groups which invite a divisive speaker may subsequently face a longer vetting process for the foreign speakers they plan to bring into Singapore.

The Presidential Council for Religious Harmony, which includes representatives of Singapore's major religions, may also be given more powers to weigh in on the entry applications of foreign speakers.

Now, foreigners on short-term work assignments related directly or indirectly to any religion must hold valid Miscellaneous Work Passes issued by the Manpower Ministry. To apply for a pass, a foreigner has to be sponsored by a Singapore-based organisation or society.

The potential changes to the Act are part of a national effort to protect Singapore's racial and religious harmony which, in turn, will help in its battle against terrorism, which has intensified in the region and the West. Observers also said the new moves would encourage organisations to be extra careful when inviting foreigners to address their congregations.

Last month, Home Affairs and Law Minister K. Shanmugam said the Act will be reviewed.

It is being done to enhance legislative provisions to protect racial and religious harmony.

Mr Shanmugam also cited two foreign Christian preachers who had applied for short-term work passes to speak here but were denied entry as they "were very Islamophobic in their statements outside of Singapore".

When contacted, the MHA said it will give details when the review is completed.

The Act, enacted in 1990, allows the Minister for Home Affairs to issue restraining orders to anyone who, for instance, undermines religious harmony. The order bars a person from addressing or advising any religious group or institution. Contravening it can result in a fine of up to $10,000, jail of up to two years, or both punishments.

No restraining order has hitherto been issued under the Act.

Law don Eugene Tan said the review shows clearly the Government wants tougher laws to deal with the increasing threats to religious harmony. "This could take the form of pre-emptive measures, more sanctions beyond restraining orders, heavier penalties as well as expanding the scope of the Act to explicitly include non-religious leaders as well."

Some experts believe the review could result in new penalties against the speakers themselves.

While there are other avenues to penalise them - namely, the Penal Code and Sedition Act - some believe strengthening the Act would let the Government act faster.

Meanwhile, religious leaders like Cornerstone Community Church's senior pastor Yang Tuck Yoong have suggested alternatives outside the Act. These include getting individual speakers and heads of religious institutions to sign guarantees or undertakings that any address by a foreign speaker will stay within the agreed topic.

Experts believe such a procedure alongside an official appeal channel could work instead of a blanket ban on speakers who have spoken on sensitive topics overseas.

Said Dr Mathew Mathews of the Institute of Policy Studies: "There should be a balance, especially if someone who used to decry other religions has re-thought his or her position and comes out to say he or she understands and admires the Singapore model of keeping peace.

"There should be processes for them to undertake they won't do and say these unacceptable things."