FILE PHOTO: Thailand's Crown Prince Maha Vajiralongkorn attends an event commemorating the death of King Chulalongkorn, known as King Rama V, as he joins people during the mourning of his father, the late King Bhumibol Adulyadej, at the Royal Plaza in Bangkok, Thailand, October 23, 2016. REUTERS/Athit Perawongmetha/File Photo

BANGKOK (Reuters) - Thailand’s parliament will hold an extraordinary meeting next week, the head of the National Legislative Assembly said on Friday, fuelling speculation that it could herald an invitation for Crown Prince Maha Vajiralongkorn to ascend the throne.

The throne has remained empty since the death of widely loved King Bhumibol Adulyadej on Oct. 13. The monarch was regarded as a pillar of stability during decades of political upheaval and rapid development in the Southeast Asian nation, which has been run by a military junta since a coup in 2014.

Prime Minister Prayuth Chan-ocha told reporters on Friday that he has asked parliament to convene a special meeting on Tuesday. Pornpetch Wichitcholchai, head of the National Legislative Assembly, told Reuters that “no details have been given on what the special meeting will handle”.

“I have to wait for the government to communicate this with the National Legislative Assembly,” Pornpetch said. He has told lawmakers not to leave the country next week.

Reuters reported last month that preparations are being made for Prince Vajiralongkorn, the late king’s designated heir, to ascend the throne on Dec. 1. A formal coronation, however, can only take place following King Bhumibol’s cremation next year.

“There is a possibility that the ascension will be announced on Tuesday. This is because on Dec. 1 and Dec. 2 there is a ceremony marking 50 days since the king’s death and that would clash. So the ascension could happen earlier,” Kan Yuenyong, executive director of the Siam Intelligence Unit think-tank, told Reuters.

According to the constitution, parliament must invite the heir to the throne to become king. In the interim, Prem Tinsulanonda, the 96-year-old former chief of the king’s privy council, has been serving as regent.