File picture: Princess Ubolratana attends the Thai Gala Night in Hong Kong. Image Credit: AP

BANGKOK: Thailand's King Maha Vajiralongkorn on Friday called his elder sister's bid to run for prime minister in March "inappropriate" and unconstitutional, likely sinking her candidacy for a populist opposition party.

Princess Ubolratana Rajakanya Sirivadhana Barnavadi, 67, stunned the nation when she announced on Friday she would be the sole prime ministerial candidate for the party, which is loyal to ousted ex-premier Thaksin Shinawatra, in the March election.

Her candidacy instantly threatened to upend the first national ballot since a military coup in 2014 that ousted a government loyal to Thaksin, the figure at the centre of years of political turbulence and rival street protests that have riven Thai society.

But the opposition from Ubolratana's younger brother, a constitutional monarch, is likely to lead to the Election Commission disqualifying her.

Thailand has been a constitutional monarchy since 1932 but the royal family has wielded great influence and commands the devotion of millions.

"Involvement of a high-ranking member of the royal family in politics, in whatever way, is an act that conflicts with the country's traditions, customs, and culture, and therefore considered extremely inappropriate," the king said in a statement.

The statement was issued by the palace and later read on air by a television announcer.

King Vajiralongkorn also cited a provision in the constitution that states the monarch stays above politics and maintains political neutrality.

"All royal family members adhere to the same principles ...and cannot take any political office, because it contradicts the intention of the constitution." Friday was the last day for parties to declare candidates.

Prime Minister Prayuth Chan-ocha, who was army chief when he led the 2014 coup and now heads the ruling junta, also announced his candidacy on Friday.

The March 24 election has been viewed as a straightforward battle between Thaksin's populists and their allies, on the one hand, and the royalist-military establishment on the other.

How it all started

Princess Ubolratana, 67,  the older sister of Thai King Maha Vajiralongkorn, was announced as a candidate for the Thai Raksa Chart party steered by the divisive Shinawatra political clan.

The Thai monarchy, a revered institution shielded from criticism by a tough defamation law, has traditionally been seen as above the political fray, although royals have intervened in moments of political crisis.

Ubolratana’s nomination has electrified the buildup to a March 24 election, which had seemed poised to return the junta and its proxies to power in some form.

It dramatically redraws the kingdom’s political landscape by giving a royal sheen to Thaksin Shinawatra’s political machine, which has won every election since 2001.

Who is Princess Ubolratana

Born in 1951, Princess Ubolratana is the oldest child of Thailand’s late King Bhumibol Adulyadej.

After marrying an American in 1972, she gave up her royal title and moved to the US. After her divorce she returned to Thailand and once again started participating in royal life.

The princess engages actively in social media and has also starred in several Thai movies.

She had three children, one of whom died in the 2004 tsunami while the other two still live in the US.

The princess has registered for the Thai Raksa Chart party, which is loyal to the controversial Shinawatra family that has dominated Thai politics for years.

Defamation laws

Thailand’s monarchy is protected by one of the world’s toughest royal defamation laws, making detailed discussion about the family’s role almost impossible inside the kingdom.

Thai Princess Ubolratana’s entry Friday as a candidate for prime minister in March elections raises questions about how the media can cover her campaign, and even how analysts or the public can discuss her publicly.

Here are some facts about lese majeste, or section 112 of the criminal code, as it is known in Thailand.

What is the law and is the princess covered?

Under “112” anyone convicted of defaming, insulting or threatening the king, queen, heir or regent faces between three and 15 years in prison on each count.

Technically, the princess would not be covered. She also relinquished her royal titles after marrying an American decades ago, before divorcing and returning to Thailand.

She is however considered a member of the royal family and performs royal duties, and 112 has been routinely interpreted to cover any aspect of the monarchy.

Prosecutions under the junta have dramatically widened what counts as lese majeste, from an academic who questioned a 16th century royal elephant duel - the charges were later dropped - to a man prosecuted for satirical comments about the former king’s dog.

“Nothing in the law indicates that it can be used to encompass other figures, including past monarchs or historical narratives connected to past reigns,” said Human Rights Watch’s senior Thailand researcher Sunai Phasuk.

“In recent years, however, Thai authorities have interpreted the law increasingly broadly without apparent support in the text of the law.”

How will coverage of the election be affected?

The princess is a public personality who has appeared in films and concerts and has an Instagram account. But given the way 112 has been broadly interpreted in the past, netizens and media outlets will think twice about what to publish.

“In the very near future we are going to see lots of self-censorship among the media, in the public and private sphere,” said Kanokrat Lertchoosakul, a political science lecturer at Chulalongkorn University.

Who enforces royal insult violations?

Prosecutions under 112 skyrocketed after the May 2014 coup by the junta which portrays itself as defenders of the monarchy. Some record-breaking sentences were handed down, the longest being 30 years in jail for a series of Facebook posts.

Anyone can make an accusation of lese majeste and the police are duty-bound to investigate. Under the current regime, many suspects are tried in closed military court and there is no avenue for appeal.

Critics say the law has been used to silence opposing voices. A cyber patrol team trawling the internet for royal insults was reinforced after the coup as part of a crackdown on dissent.

What’s the situation under the new king?

Convictions have declined in recent months, suggesting a change in attitude towards the defamation law under the rein of Ubolratana’s brother King Maha Vajiralongkorn, whose coronation is set for May.

Six young Thais accused of setting portraits of the royal family on fire were granted rare acquittals in September, though they also faced a raft of other serious charges.

One expert said convictions had reached record lows in 2018 to the point where they were almost non-existent. There were four acquittals in 2018 and no new cases, according to legal monitoring group iLaw.

But many are still serving time or in self-exile after being accused of the offence.