BANGKOK, THAILAND - The leader of Thailand's "Yellow Shirt" protesters, an arch-rival of fugitive ex-premier Thaksin Shinawatra, was Tuesday voted leader of the movement's new political party, the group said.

Sondhi Limthongkul, who led a blockade of Bangkok's airports last year to drive Thaksin's allies from government, was elected unopposed to lead the New Politics Party at its first general meeting, a spokesman announced.

"Here meet our new leader Sondhi," Somsak Kosaisuk told the gathering in the Thai capital, broadcast live on ASTV - the television channel owned by Sondhi.

The election came a few days after the media mogul, who faces a raft of libel cases by people he has criticised, was handed a jail term.

In his latest trial, he was handed a six-month jail sentence on Friday for defaming former Thai foreign minister and Thaksin ally Noppadon Pattama, but was granted bail while he appeals against the verdict.

His ardent royalist party, formerly known as the People's Alliance for Democracy (PAD), has said its aim is to promote a "clean politics" free from corruption, symbolised by adding green to the yellow of its group logo.

"We will make the New Politics Party change politics for our next generations," Sondhi told party members following his election.

The Yellow Shirts helped topple prime minister Thaksin Shinawatra with mass rallies in 2006 and reformed with tens of thousands of yellow-clad supporters last year to protest against his allies in government.

The 2008 demonstrations peaked in the seizure of Bangkok's two main airports in late November-early December, which left more than 300,000 travellers stranded in Thailand for more than a week and caused crippling economic damage.

As the PAD, the group had the support of Bangkok's elite and circles in the palace, military and bureaucracy, who loathed Thaksin.

Thaksin, supported by the rival "Red Shirts" in Thailand's colour-coded politics, fled the kingdom last August to avoid a two-year jail term for corruption.

Sondhi survived an assassination attempt in April which he blamed on elements in the country's security forces.