Tens of thousands of anti-government protesters in Thailand staged rallies yesterday at more than a dozen locations in Bangkok, including government ministries and the police and military headquarters, to call for the ouster of Prime Minister Yingluck Shinawatra and her Puea Thai-government.

Puea Thai won the 2011 elections with a large majority, mainly on the vote of the economically deprived and populous rural areas of the north and north east of Thailand, and sections of the urban poor. Yesterday’s protests followed a rally on Sunday of about 100,000, drawn mainly from more middle class layers in Bangkok and protesters bussed from southern Thailand, the stronghold of the opposition Democrat Party.

The political situation in the capital is tense. Around 50,000 pro-government supporters organised by the United Front for Democracy against Dictatorship (UDD) or “Red Shirts” have gathered at the capital’s Rajarnangala Sports Stadium. UDD leaders say more people are on the way to the city from Thailand’s north and north east.

Yingluck has called for calm, saying the issue should be settled through a parliamentary no-confidence debate, which is due to take place today.

The demonstrations began a month ago in opposition to the government’s amnesty bill. The protests are being led by Suthep Thaugsuban, who resigned as a member of parliament to organise the opposition. Also involved are right-wing, pro-monarchist groups, including the Peoples Democratic Force to Overthrow Thaksinism, which is dominated by retired senior military officers.

Layers of the country’s traditional establishment—the military, the monarchy and state bureaucracy—are deeply hostile to the amnesty bill, claiming it would allow Yingluck’s brother, former Prime Minister Thaksin Shinawatra, to return to Thailand from self-imposed exile. At yesterday’s protests, Suthep declared: “What we want is to get rid of the Thaksin system.” Some demonstrators chanted: “Thaksin get out, army come in.”

The anti-government movement has been encouraged by the defeat of the amnesty bill in the Senate, the parliamentary upper house, on November 11. This was followed by a Constitutional Court ruling on November 20 to declare unconstitutional a government attempt to change the 2007 constitution to transform the Senate into a fully-elected body.

The 2007 constitution was imposed during 14 months of military rule after the September 2006 coup that ousted Thaksin and outlawed his Thai Rak Thai (TRT) party, which had won two general elections. Thaksin, a billionaire businessman, was convicted on corruption charges and went into exile to avoid jail.

The coup was the outcome of bitter feuding in the ruling class over the direction of economic policy. The traditional elites resented Thaksin’s further opening up of the country to foreign investment following the Asian financial crisis of 1997-1998 and his undermining of longstanding systems of political patronage.

These layers were also concerned that Thaksin’s populist policies would encourage social and political unrest. His TRT established a base of electoral support among the urban and rural poor through limited handouts, including cheap health care and village loans.

Despite the biased character of the 2007 constitution, the pro-Thaksin Peoples Power Party (PPP) won the December 2007 election, provoking a new round of political upheaval. Anti-government protests by the so-called “Yellow Shirts” laid the basis for the removal of two PPP prime ministers and finally the PPP’s dissolution in what were in effect judicial coups. In December 2008, with the military’s active involvement, Democrat leader Abhisit Vejjajiva was installed as prime minister.

The anti-democratic measures used to oust the PPP governments enraged Thaksin’s support base, leading to mounting protests in Bangkok by the UDD’s Red Shirts and clashes with the police and military. In 2010, on May 19, the army violently attacked and broke up a longstanding protest encampment in the capital’s business district, killing more than 90 people and injuring some 1,500.

Both factions of the ruling elite then sought to defuse the political crisis, fearing that the involvement of layers of the working class and rural poor would spiral out of their control. Before the 2011 election, the two factions struck a deal to allow Puea Thai, the PPP’s successor, to take office if it won. In return, the interests of the monarchy and the military would be protected.

The re-emergence of factional infighting in Bangkok is a reflection of the social and political tensions being generated by faltering economic growth. The amnesty bill appears to have been the product of some backroom wheeling and dealing between the competing factions, but in the end it did not satisfy the hardline elements of either camp.

The government alienated significant sections of its own supporters. The amnesty bill originally proposed by Puea Thai MP Wocharai Hema would have pardoned the Red Shirt protesters but not their leaders, nor the Democrat and military leaders responsible for the May 2010 killings. However, when Puea Thai leaders brought the legislation to parliament, it had been changed to grant amnesty to Thaksin, the Democrat leaders and the military killers, but not UDD-Red Shirt leaders serving or facing jail sentences.

The amendments provoked an angry reaction from the Red Shirt followers who wanted those responsible for the 2010 massacre to be charged, and regarded the charges against the UDD leadership as unfounded. The government rammed the legislation through the lower house by directing all its MPs to turn up and vote for it. In the event, four Puea Thai members abstained, including Deputy Agriculture Minister Nattawat Saikua.

Prominent Red Shirt leader Prasang Monkonsiri denounced Puea Thai parliamentarians who supported the bill as “traitors” and “whores” for defiling the “hundreds of ghosts you led to their deaths.” Under these conditions, when the Senate voted on the bill, all 141 senators present voted it down. The government had already agreed to remove the legislation.

The government then sought to amend the constitution to transform the Senate into a fully elected body. Currently, 74 of the 150 senators are appointed by a panel, drawn from the judiciary and state bureaucracy. The proposed amendment passed the lower house and the Senate, and was being considered by the head of state, King Bhumibol Adulyadej, but was challenged by opposition politicians as unconstitutional.

The Constitutional Court’s 5-4 ruling against the amendment bill was clearly a political decision. The judgment upheld the opposition petition’s claim that the legislation violated Section 68 of the 2007 constitution, prohibiting attempts to overthrow the monarchy or affect the king’s status as head of state. The judgment declared that turning the Senate into an all elected chamber would “allow politicians to take total control of the parliament” and thus undermine the position of the monarchy.

At the same time, the court rejected other opposition petitions demanding action against those responsible for the amendment bill, including the dissolution of the ruling parties and the disqualification of their members of parliament from office. Taken together, the rulings were clearly a political balancing act designed to try to appease both the government and the opposition. The large, ongoing pro- and anti-government protests, however, indicate that nothing has been settled.