The sister of Thailand's King Maha Vajiralongkorn has been declared as a leading prime ministerial candidate for a party loyal to ousted prime minister Thaksin Shinawatra in March 24 elections, registration papers showed on Friday.
Princess Ubolratana Rajakanya Sirivadhana Varnavadi, 67, broke the long-standing tradition of Thai royalty staying out of politics by entering the election in an unprecedented move.
Thailand has been a constitutional monarchy since 1932 but the royal family has wielded great influence and commanded the devotion of millions.
The king's eldest sister has registered as a candidate for the Thai Raksa Chart party, an off-shoot of the Thaksin-backed Pheu Thai Party. The election is seen as a battle between Thaksin's populists and allies and the royalist-military establishment.
Separately, the head of Thailand's military junta, Prayuth Chan-ocha, said on Friday he will contest the March elections as a candidate for prime minister.
Prayuth, the army chief who seized power from a democratic government in a 2014 coup and made himself prime minister, said in a statement he would run as a candidate for the pro-military Palang Pracharat.