Thailand’s political roller coaster has taken a sharp downward turn, with the country’s constitutional court forcing Prime Minister Yingluck Shinawatra (pictured) and a number of ministers to resign over an alleged “abuse of power”, in what her supporters are calling a constitutional coup. A caretaker prime minister has been appointed by the remaining cabinet, but the country now appears to be headed towards a political showdown.

The court’s ruling, over the transfer of a senior security official in 2011, was marked by rushing proceedings and not allowing Yingluck to present key witnesses in court. The ousted prime minister’s supporters have claimed since the proceedings were first initiated that they were being orchestrated by anti-democratic forces.

It has been reported in the Thai media that the anti-government demonstrations, which had been disrupting Bangkok, were funded by figures who wish to see the country’s royal family have an active role in Thai politics. Anti-government protesters have been calling for the replacement of the government with a non-elected “people’s council”.

Although always deeply opposed to the Shinawatra family’s grip on political power, the anti-government group was roused to new levels of anger when Yingluck Sinawatra presented a bill to Parliament granting amnesty for her brother, former prime minister Thaksin Shinawatra, over a corruption conviction. The amnesty would have allowed Thaksin to return from self-imposed exile. Thaksin was ousted as prime minister in a coup in 2006 and was subsequently convicted of corruption.

Opposition forces were further angered when Yingluck attempted to change the 2007 constitution to make Parliament’s upper house fully elected, as it was before the 2006 coup, rather than partially appointed. Such a move would have broken the entrenched power of Thailand’s conservative elite, which has been behind the recent anti-government protests.

Yingluck’s Pheu Thai Party, already dominant in the lower house, would have been likely to have been handed a majority in both houses of Parliament had the move succeeded. However, at the urging of the opposition Democratic Party, the conservatively aligned courts overruled the constitutional amendment last year.

Thai politics has been increasingly characterised as a division between pro-government “red shirts” and anti-government “yellow shirts”, defined by the former’s power base in the north and north-east of the country and among Bangkok’s working class, and the latter among Bangkok’s middle and upper classes and the south of the country.

However, the divisions also run to views on the role of the monarchy, with succession to the frail King Bhumibol Adulyadej increasingly imminent, patronage networks, the role of the military and police, and a range of other economic, social and cultural factors. While this complex of factors had earlier ensured some fluidity in Thai politics, positions have increasingly hardened and divided since Thaksin’s ouster in 2006.

The “constitutional coup” against Yingluck Shinawatra will only further entrench those divisions. Red shirt supporters are now planning to march on Bangkok, in a reversal of the tactics that plunged the capital into chaos from late last year.

In a state of political flux, the opposition will now be pushing for the establishment of its proposed “people’s council”, to which its members would be appointed. This is their preferred alternative to going to fresh elections and again facing the prospect of defeat.

Historically excluded from the levers of power, Thailand’s poor have, through the patronage of the Shinawatra family, experienced some of the economic benefits of political power. They now seem to be reluctant to give up such benefits without a fight.

Having experienced the effectiveness of the yellow shirts’ mass protests and building occupations, the red shirts can be expected to try something similar soon. The only question will be whether Thailand’s traditionally more conservative security forces show as much restraint against the red shirts as they had against the yellow shirts.

In any case, Thailand’s experiment with democracy, so promising at so many levels, now appears to be all but permanently broken. It may, perhaps, be restored, if in a diminished sense. But the idea that a majority of people can choose a government without restriction now appears to have been removed from Thailand’s political agenda for the foreseeable future.

*Professor Damien Kingsbury is director of the Centre for Citizenship, Development and Human Rights at Deakin University