Prime Minister Najib Abdul Razak criticised his predecessor Dr Mahathir Mohamad and others for going against their own principles in asking for foreign intervention .

"Now, I know that there are some who would like you to think that our economy is in trouble.

"Some, who, against their own principles, even asked for foreign intervention," Najib said, without naming Mahathir.

"Some who ought to know better have been talking down about Malaysia.

"Indeed, they do know better. Malaysia is sustainable at the core. Because the facts - including those I have just outlined to you - are indisputable," he said in his keynote address at Invest Malaysia 2016 in Kuala Lumpur.

Najib said these people have their own agenda and placed their personal interests above the interest of the country.

"To them, damage to the country is just collateral. To them, the end always justifies the means. They have been airing all sorts of wild allegations," he said.

The prime minister stressed that the government's plan, which included six Strategic Reform Initiatives, 12 National Key Economic Areas (NKEA) of the Economic Transformation Programme, is still working.

"We can say with certainty that our economic plan is working," he added.

Mahathir ( photo ) yesterday denied calling for foreign intervention to oust Najib.

"I did not ask any foreign government to interfere. I said that all the means to redress in this country have been shut down by Najib. So, I will tell the foreign press about this," Mahathir was quoted as saying by Star Online .

IMF praised Malaysia

Najib also proudly pointed out that his political opponents might be surprised how the ringgit against US dollar has performed.

"The ringgit is Asia's best performing currency this year to-date. This may surprise my political opponents, who said that if I continued in my job the ringgit would fall to RM4.80 to the dollar. Now, it's RM3.88 to the dollar," he said.

Citing International Monetary Fund (IMF) which praised Malaysia for its prudent monetary policy, and a World Bank regional director who expressed confidence in Malaysia, Najib linked the success to the implementation of the goods and services tax (GST).

"We are very appreciative of these accolades. But they are recognition of achievements that have not come to pass by chance and good luck.

"They are the result of our economic plan, and of the government's continuous efforts to make Malaysia a business-friendly environment.

"That has involved reforms and diversifying both the economy and government revenue. This is why we introduced GST last year," he said.

While acknowledging that GST was not a popular move, Najib reiterated that it was necessary for a responsible government to make tough decisions that are right for the country.

"The people who are opposed to it here knew that they were wrong, for populism and opportunism can never be the right reasons for the government to take," he said.