The two-page letter, headed "Why did I criticise the Prime Minister?", was addressed to the "Citizens of Malaysia".

"In a situation where no one can criticise the prime minister, I have to voice my criticisms on matters that do not concern my personal being, but only those that concern the interest of the religion, race and country," he said.

In his letter, which he signed off as a "Malaysian citizen and commoner", Mahathir listed four manners in which he had allegedly been blocked from criticising Abdullah.

He claimed that Umno, non-governmental organisations, associations of government and non-government officers, universities and other institutions were forbidden to invite him to their functions.

"Every time anything that involves the public takes place, the deputy prime minister and certain other quarters will forcefully advise that any criticism, comment or debate should stop," he said.

Claiming there was a climate of fear in the country, Mahathir said the questions and issues he had raised had not been answered and that what was being questioned was his right to comment and criticise.

He said attempts had been made to disparage him "so badly that I am made out to be of unsound mind. Repeatedly, allegations were made that the administration during my time was worse."

The former prime minister, who led the country for 22 years, said the media had also called his criticisms despicable and reprehensible.

"My meeting with him [Abdullah] should be kept secret from the rakyat ["people"]. And because we have met, I can no longer criticise whatever is done by the prime minister," he said.

In ending his letter, Mahathir said he had been forced to release a written statement so that it was not spun by anyone as all avenues for criticising the government had been closed to him.

The Star/Asia News Network

Kuala Lumpur