Dec. 4 (Bloomberg) -- Thailand’s King Bhumibol Adulyadej, the world’s longest-reigning monarch, did not give his annual birthday address because he is “slightly ill,” Crown Prince Maha Vajiralongkorn said. The monarch turns 81 tomorrow.

The king has an inflamed windpipe and alimentary canal and is on a saline drip because he cannot eat, said Crown Princess Maha Chakri Sirindhorn.

“He would like to take a rest today,” Princess Sirindhorn told officials at an event broadcast live on national radio. “He was fine yesterday.”

The king, whose picture is hung in most Thai homes, has often used his birthday speech to address national issues. Many looked forward to his address after months of anti-government street demonstrations by royalist protesters that culminated in the seizure of Bangkok’s airports, and a court ruling this week that ousted the prime minister.

“A crucial date in the Thai political calendar has been missed,” said Michael Montesano, a visiting research fellow at the Institute of Southeast Asian Studies in Singapore. “The vacuum created by his not appearing may be an indicator of vacuums to come in the future.”

Sieges

Anti-government demonstrators seized airports and took over the prime minister’s office in a 192-day campaign that ended Dec. 2 against allies of former Prime Minister Thaksin Shinawatra, whom they accused of trying to turn the country into a republic. The Constitutional Court disqualified Prime Minister Somchai Wongsawat, Thaksin’s brother-in-law, two days ago when it dissolved his ruling People Power Party for vote buying.

“Political watchers will be scrutinizing his message for what he says or doesn’t say, which could ultimately influence the outcome of the current political stalemate,” Mark Tan, an analyst for Goldman Sachs Group Inc. in Hong Kong, said in a report earlier this week.

More than 20,000 people, including the king’s top aide Prem Tinsulanonda, Acting Prime Minister Chawarat Charnveerakul, and Constitutional Court President Chat Chalaworn were among those waiting for him today at a ceremonial palace in Bangkok.

Bhumibol was hospitalized for 25 days until Nov. 7 last year for insufficient blood flowing to his brain after scans found minimal cerebral ischemia on the left side of the brain. He briefly spoke yesterday at the Trooping the Color, where the King’s Guard pledges allegiance to the monarch.

Parables

Under Thailand’s constitutional monarchy, the king is head of state while the prime minister and parliament govern. All legislation must still be approved by the king.

Though the palace portrays the king as being apolitical, he had advised Thai governments through speeches and writings that often used parables to address corruption, environmental damage and help for the poor. In 1992, after troops fired on pro- democracy demonstrators, millions of Thais watched on television as rival leaders prostrated themselves before the king.

In April 2006 the monarch told top judges it was their job to take a more active role in political affairs. The courts have since nullified an election won by Thaksin’s party, disbanded two parties tied to him and disqualified two prime ministers supported by his allies.

The king’s birthday provides a respite in the battle for power between the ruling party and protesters backed by the capital’s royalist elite. The third Thaksin-linked prime minister in four months may be elected by lawmakers next week, a move that will likely bring protesters back on the streets.

Struggles

Non-executive members from People Power will probably jump to a new shell party created as a refuge for pro-Thaksin lawmakers called Puea Thai. The party will choose a new leader on Dec. 7. If the six-party coalition sticks together, Thaksin’s allies may return to power by forming the third government since they won last year’s election on heavy rural support.

The People’s Alliance for Democracy vowed to resume demonstrations if a new government linked to Thaksin returns. The group is composed mostly of the Bangkok middle class, royalists, civil servants and southerners who support the opposition Democrat party.

Queen Sirikit presided over the funeral of a protester killed in clashes with police on Oct. 7 and said she would pay the medical expenses of injured demonstrators. Many demonstrators have worn yellow, the color that symbolizes the king, during the six-month protests.

‘Really Listen’

“We need the political parties and the protesters to really listen to the king, and to try to understand,” Pramon Sutivong, president of the Thai Chamber of Commerce, said in an interview before Bhumibol was scheduled to speak. “People interpret the speech for their own benefit because the king is sometimes vague. He cannot be so specific.”

Three months before the 2006 coup against Thaksin, Bhumibol’s top adviser Prem said soldiers should be loyal to the king instead of the government. Last week, the army and police ignored the government’s orders to disperse protesters from the airports.

Since Bhumibol took the throne as an 18-year-old in 1946, the country has seen 23 prime ministers and nine coups. Only two of 17 Thai constitutions since absolute monarchy ended in 1932 have mandated fully elected parliaments.

God Like

During his six decades on the throne, Bhumibol has achieved near god-like status. His many trips to rural areas combined with strict laws against insulting him and a public relations campaign that extended from history books to nightly newscasts propelled him to unrivaled popularity.

Movie-goers must stand for the royal anthem before films at Thai cinemas. Failure to comply could invite wrath from fellow audience members and up to 15 years in prison according to Thai laws that prevent anyone from insulting the king.

Thailand’s constitution says the king “shall be enthroned in a position of revered worship and shall not be violated.” Bhumibol’s statement in 2005 that he could be criticized has not stopped a stream of lese majeste lawsuits, one of which forced a cabinet minister to resign in May.

To contact the reporter on this story: Rattaphol Onsanit in Bangkok at o ronsanit@bloomberg.net

Last Updated: December 4, 2008 07:19 EST