Thailand is facing a period of heightened political uncertainty after its king publicly discouraged his sister from running for prime minister. The headlines started pouring in on Friday when the Thai Raksa Party, a populist group associated with former Prime Minister Thaksin Shinawatra, announced that Princess Ubolratana Rajakanya, the elder sister of King Maha Vajiralongkorn, would run as its prime ministerial candidate in the March 24 general election. Shortly thereafter, current Prime Minister Prayut Chan-ocha who represents the ruling military government, also threw his hat into the ring under the pro-military Palang Pracharat Party. But then the king came out against his sister's candidacy, saying in a statement that it was "inappropriate" for members of the royal family to enter politics. Then, over the weekend, people on the ground reported sightings of military vehicles around Bangkok, fueling worries that some sort of power grab could be brewing. "There's been so many coups in Thai history that when you see military vehicles on the street, something must be up," said Paul Chambers, a lecturer for international affairs at Thailand's Naresuan University.

A man wearing a Thailand Vote shirt uses a smartphone at the office of the Election Commission in Bangkok on Feb. 8, 2019 Brent Lewin | Bloomberg | Getty Images

On Monday, the ruling government called the coup rumor "fake news" in the wake of the term #ThaiCoup trending on Twitter in the country, according to news wires Deutsche Presse-Agentur and Agence France-Presse. Authorities said the military vehicles were being moved for an annual multinational military exercise that begins on Tuesday, multiple reports said. It's not entirely clear why the military would have needed to forcibly take control. In 2014, the army seized power from a pro-Thaksin government with Prayuth, now a retired general, leading that movement. And, in its five years of rule, the military leadership has delayed elections several times. The March 24 vote is seen as a test of the country's ability to return to democracy. One reason for the coup rumors could be infighting between factions of the armed forces, Chambers suggested: "There has been a growing divide in the military over the junta government." Another cause for the show of force could be anticipation of political unrest, according to Andrew MacGregor Marshall, lecturer at Edinburgh Napier University and a leading expert on Thai politics. The king, who traditionally commands the allegiance of the military, "may feel that recent events have thrown the election process into chaos, and he does not want political disarray to overshadow his coronation in early May," Marshall said on Twitter. There's also a risk of Princess Ubolratana's Thai Raksa Party getting kicked out of the electoral race, which could raise tensions. On Sunday, Srisuwan Janya, secretary-general of Thailand's Association for the Protection of the Constitution, told Reuters that he would file a petition to disqualify the group. "The royal announcement made it clear that the party violated electoral law," the activist told the news agency, referring to the king's Friday statement, which said her action amounted to a violation of the constitution.

The monarch's pronouncement on Friday said members of the royal family cannot "be permitted to hold any political office because this would violate not only the spirit of the Constitution, but also the established conventions of government under the rubric of constitutional monarchy," according to a translation posted on the Ministry of Foreign Affairs website. That rebuke triggered questions about to what extent the monarch had been made aware of his sister's intentions. "Did Thaksin and his allies go forward with their plan with Ubolratana without the king knowing — which would be an unbelievably bold move, given the vast power of the Thai monarchy?" Joshua Kurlantzick, senior fellow for Southeast Asia at the Council on Foreign Relations, asked in a recent note. "(Or) did Thaksin, the princess, leaders of pro-Thaksin parties, and the king strike a deal, only for the king to walk away at the last minute—perhaps due to some royalists' distrust of Thaksin?" Kurlantzick continued.