KUALA LUMPUR, Feb 12 — Moderates in Malaysia must challenge voices of extremism or risk allowing them to dictate how society functions, former prime minister Tun Dr Mahathir Mohamad said today.

He told Malaysians professing to be moderate that the country will eventually be taken over by extremists if the former group continues to remain silent over the growing tide.

"The problem with what the extremists are saying is that the moderates don't dare to talk back.

"They fear that if they do talk back, they would be subject to the extremists attack and tirades... but if you don't talk back you, you let it be that the extremists would dominate society," he told a Centre for A Better Tomorrow-organised forum entitled "A Malaysian Dilemma" here.

The former prime minister then highlighted the group of 25 former senior civil servants pressing Putrajaya to roll back Islamisation of the country, noting that more of such groups were needed to battle out extremism.

"They are speaking up against problems like the Islamic law. I think that is good that they are doing this," he said.

Dr Mahathir pointed to one example of what he perceived to be a form of extremism: The controversy around Muslims wishing their Christian counterparts "Merry Christmas".

He criticised the idea and said it was against the teachings of Islam, a religion that is intended to promote peace among all humans.

"So what next? You have to ban the Chinese saying 'Selamat Hari Raya' because the Chinese have to be Muslims first before they can wish it," he said in his usual sarcastic tone.

Religious tensions have been on the rise in Malaysia in recent years, and exacerbated by the rise of Malay and Islamist groups such as Isma and Perkasa pushing religious fundamentalism under the professed aim of defending Islam.

Ironically, Dr Mahathir has also been labelled a Malay extremist due to his affiliation with Malay rights group Perkasa.

He acknowledged the accusation today but maintained that he has always been a moderate.

The former prime minister claimed he is among the moderates who are rebutting the assertions of extremists, particularly those from the Chinese community.

"You know there are three groups of extremists here," he said, referring to the country's three main major races.

"We need to rebut the extremists. But when I rebut they call me an extremist. They even call me a racist," he joked.