Thailand’s military took control of the country’s main broadcaster at 6 a.m. today and declared martial law throughout the country. It then seized all radio and TV stations. Thousands of troops were mobilised throughout Bangkok, where pro- and anti-government protesters have held mass rallies for the past fortnight.

The military declared that its actions were “not a coup” but were taken “to preserve law and order” and called on the public not to panic. These statements cannot be taken at face value, however.

The army—which has staged 18 coups or attempted coups since the 1930s—intervened without consulting the elected Pheu Thai government. Its actions are yet another step in a six-month campaign to oust Pheu Thai and install a dictatorship. The first order of Army Chief General Prayuth Chan-ocha was to dissolve the government-controlled security agency, the Centre for the Administration of Peace and Order.

US State Department spokesperson Jen Psaki endorsed the declaration of martial law, stating: “We expect the army to honour its commitment to make this a temporary action to prevent violence, and to not undermine democratic institutions.” In reality, the military is setting the stage for the ouster of the elected government, either directly through a coup, or indirectly via the Senate or the courts—with Washington’s tacit support.

The army has given itself the power to ban public gatherings, search any premises and vehicles, enforce curfews, censor the media, and interrogate and detain anyone it likes. Jatuporn Prompan, leader of the pro-government United Front for Democracy Against Dictatorship (UDD), told Agence France-Presse that its rally site on the outskirts of Bangkok, where tens of thousands of Red Shirts are gathered, was “surrounded by troops on all sides.”

The government downplayed the threat of a coup. Acting justice minister Chaikasem Nitisiri told Reuters: “It’s good that the army is looking after the country’s security. However, the government still has full power to run the country.”

The pretext for declaring martial law was last Thursday’s grenade attack on the anti-government People’s Democratic Reform Committee’s (PDRC) rally site in central Bangkok. Three people were killed and 23 injured. It was the latest in a string of attacks on demonstrators, for which no one has been arrested. While the PDRC blames Red Shirt supporters for the attacks, it has far more to gain by staging a provocation in order for the army to step in.

Since December, General Prayuth has repeatedly stated that he was prepared to lead a coup if violence broke out between the PDRC and the Red Shirts. While the army claims to be “neutral,” it obviously supports the PDRC. It recently allowed the PDRC leaders to occupy a wing of Government House. A number of soldiers have joined the ranks of the PDRC’s “security guards.”

The PDRC and its allies, including the opposition Democrat Party, the unelected lawmakers in the Senate, the judiciary and much of the state bureaucracy, have campaigned for six months to topple the government and install an unelected “people’s council”—which would be nothing other than a military-backed junta.

The PDRC disrupted the February election, which was boycotted by the Democrats and later annulled by the Constitutional Court. The court then removed Prime Minister Yingluck Shinawatra and nine cabinet ministers on the trumped-up charge that they unlawfully transferred a senior security official from his post.

The PDRC and Democrats represent Thailand’s traditional elites—the military, the monarchy and the bureaucracy—who backed the coup in 2006 that overthrew Prime Minister Thaksin Shinawatra, Yingluck’s brother. Thaksin, a telecommunications billionaire, fell foul of the country’s more powerful vested interests when he opened up the economy to further foreign investment.

He and Yingluck also won support among the rural and urban poor on the basis of limited concessions—including subsidies for rice farmers and cheaper healthcare. Amid a deepening economic crisis—exacerbated by months of political instability—big business is demanding that these reforms be scrapped.

On Monday, the National Economic and Social Development Board announced that the economy shrank by 2.1 percent in the March quarter, following a contraction of 0.6 percent in the December quarter. This compares with 6.1 percent first quarter growth in neighbouring Malaysia.

The PDRC has promised the Bangkok elites and international investors that its “people’s council” will re-write the constitution to outlaw the Shinawatras’ reforms and all “populist” measures in future. This agenda, which would entail the impoverishment of millions of people, cannot be imposed democratically.

The army’s intervention follows calls by Senate leaders for the resignation of caretaker Prime Minister Niwattumrong Boonsongpaisan and his government. The Senate would then install an “interim” administration to carry out the PDRC’s “reforms.” Niwattumrong yesterday told the Senate he would not step down.

The government is increasingly besieged and unable to function. Last Thursday, about 100 PDRC members, including the group’s leader Suthep Thaugsuban, stormed a meeting between the government and Election Commission (EC), forcing Niwattumrong and other officials to flee. According to media reports, riot police stationed outside the air force academy, where the meeting was held, allowed the protesters to enter.

The government wants a re-run election on July 20, but following the meeting the EC—which tacitly supports the opposition—said this was “highly unlikely” to happen because the PDRC has promised to disrupt a poll.

The brazen campaign to oust the elected government has been able to proceed because Pheu Thai and the UDD have demobilised their supporters among the urban and rural poor. As the anger of Red Shirt supporters of the government has mounted, the UDD has held only limited protests, on the outskirts of Bangkok, so as not to “provoke” the military.

Yesterday marked the fourth anniversary of the army’s bloody crackdown on Red Shirt protests in Bangkok in 2010. At least 90 people were killed, and thousands were injured, during months of protests against the military-backed Democrat government. This year, the UDD instructed the Red Shirts to stay away from the city centre where the massacre took place in order to avoid clashes with the opposition protests.

The UDD leaders have repeatedly downplayed the risk of a coup. On Saturday, UDD leader Tida Tavonseth told a press conference that the Red Shirts would remain at their rally site and not try to defend the government “because it is not our duty.” She appealed to “the police and the military... [to] please do their duty to protect the peace.”

UDD leader Jatuporn told Reuters today that the imposition of martial law was “fine.” He called on the Red Shirts to cooperate with the army.

The UDD and Pheu Thai, no less than their opponents, represent the interests of big business and are deeply afraid that Red Shirt protests could get out of hand. In 2010, as today, the UDD leaders limited their agitation to calls for an election, but the working class and rural masses began to raise their own demands for an end to social inequality.