BANGKOK - Former Thai prime minister Tanin Kraivixien has been named as the new president of its privy council.

He takes over from General Prem Tinsulanonda, who is now standing in as regent, pending Crown Prince Maha Vajiralongkorn's accession to the throne.

After Thailand's revered King Bhumibol Adulyadej, the world's longest reigning monarch, died on Thursday (Oct 13), the heir apparent asked for some time to mourn with the people before ascending the throne.

This triggered a legal clause requiring then privy council president Prem, 96, to handle royal duties as a temporary regent.

The positions of privy council chief and regent cannot be held by the same person.

Mr Tanin, 89, is a former supreme court judge and staunch anti-communist who was made prime minister after a military coup was staged in 1976 following a massacre of left-wing student protesters in Bangkok.

His own administration was upended by another coup in 1977. That was the same year he was appointed by King Bhumibol to the privy council.

Last year, Mr Tanin wrote a letter to Prime Minister Prayut Chan-o-cha in which he urged the government to bar corrupt politicians for life and to seize their assets.

According to Thai media reports, he has also supported the idea of building a canal across southern Thailand that would allow international cargo to bypass the Malacca Strait and boost Thailand's standing as a transportation hub.