Former prime minister Dr Mahathir Mohamad says opposition to naturalising migrants in Sabah is unfair and political.

In a blog posting today, he said the population boom in Sabah was justified as many of the migrants had lived in the state for a long time and they and their children were fluent in the Bahasa Malaysia.

NONE "On the basis of the length of stay and mastering of the national language, they qualify to be citizens of this country, and so the acquired citizenship," he said.

In comparison, Mahathir said, citizenship have been given to those who were not fluent in Bahasa Malaysia but have lived in Malaysia for a long time.

"So why cannot the migrants of Sabah who have all these qualifications be accepted as citizens? The objections to them being accepted seem to be political," he said.

The blog posting comes ahead of Prime Minister Najib Abdul Razak's planned visit to Sabah this weekend, during which he is also expected to finally announce the terms of reference for the royal commission of inquiry on illegal migrants being made citizens in Sabah.

Mahathir had been linked to Project IC, a name given to the alleged citizenship drive to naturalise illegal migrants for political purposes, which started in the 1990s.

Malaysians forget they too have foreign origins

Parti Bersatu Sabah had at a National Human Rights Council roundtable presented a study into the population boom in Sabah, showing that in 2002, more than 200,000 foreigners left Sabah without documentation.

However, they returned with legal documents under different names and destroyed the papers once they expired, PBS supreme council member Dr Chong Eng Leong said when presenting the study.

Mahathir claims to have " little knowlege " about Project IC, while his then deputy and now PKR de facto leader Anwar Ibrahim said he was kept out of the loop on this.

In his blog posting, Mahathir claimed that choosing not to naturalise migrants in Sabah was also racist, and that Malaysians should accept that their fellow citizens may come from different backgrounds.

He added that many Malaysians forget they have "foreign origins", from India, the Arab world, Indonesia, Turkey and even Europe, but all are now accepted as indigenous to Malaysia.

"There was a time in the distant past when parties based on ideology contested in elections. They were all rejected in favour of race-based parties.

"If we don't want our politics to be race-based, then we must forget our racial origins, speak the national language as our mother tongue and swear allegiance only to this country," Mahathir said.