Teargas and blood have again come to Bangkok as Thailand enters yet another stage of violent protests, leaving at least three dead and reopening wounds of social conflict that run deep in a bitterly polarised political system. Anti-government protesters have been laying siege to government buildings for days in a desperate bid to overthrow prime minister Yingluck Shinawatra.

Protest leader Suthep Thaugsuban issued an ultimatum to Yingluck on Sunday to step down within 48 hours.

Suthep leads the People's Democratic Reform Committee (PDRC) and is a former deputy prime minister in the previous military-installed Democrat government of Abhisit Vejjajiva.

Yingluck is the sister of ousted premier Thaksin Shinawatra, whose Thai Rak Thai party won two landslide elections in 2001 and 2005, and was on course for another victory in snap elections in 2006 only for his government to be forced out by a military coup that year.

When elections were finally called, in December 2007, Thaksin's supporters formed the People's Power Party (PPP) which won 233 seats to the Democrats 165.

The PPP created a series of short-lived coalitions with minor parties but the country became increasingly ungovernable as the Yellow Shirts organised mass mobilisations to destabilise the PPP governments.

Reconstituted as the Pheu Thai party, Thaksin supporters swept Yingluck into power in 2011 general elections, which themselves came a year after months of massive Red Shirt protests that ended when the army shot down pro-Thaksin protesters and turned parts of central Bangkok into a battlefield.

Suthep and his supporters have violently denounced what they call the "illegitimate Thaksin regime" that Yingluck heads.

The two sides, whose political movements have taken a bewildering variety of names over the years, are most easily identified by colour. The royalists generally chose the king's favourite hue of yellow, while the pro-Thaksin camp favoured red.

So has the wheel turned full circle? are the Yellow Shirts now the heroes of popular protest against a deeply unpopular authoritarian government?

Not quite. Despite the popular and democratic labels, Suthep has emerged as a spokesman for the most reactionary elements of the royalist right, effectively calling for the restoration of an absolute monarchy with a palace-nominated government.

Notably none of the anti-government protests are demanding fresh elections.

The royalist right is well aware this would most likely result in a fresh mandate for Yingluck.

Instead Suthep wants to replace the electoral system with a "people's council" or assembly that would represent "all professions."

"If we take down the Thaksin regime tomorrow, we will set up a people's council the day after tomorrow.

"Let the people's council pick a good man to be the prime minister, good men to be ministers.

"Make it a dream team, make a cabinet of your dream and the people's government," he said recently.

Suthep comes from a wealthy land-owning family in Thailand's southern province of Surat Thani, now a major tourism centre, especially the two islands of Ko Samui and Ko Phan Ngan.

It is Thailand's southern provinces that provide the main electoral support for the Democrats. The north and north-east are strongly pro-Thaksin.

Bangkok is home not only to the country's ruling elite, fiercely anti-Thaksin in general, but also a large marginalised migrant community from the north-eastern provinces, combined with a substantial urban poor population. This is why the clashes have been mostly centred in Bangkok.

The immediate cause of the unrest was an ill-conceived amnesty Bill. This Bill would have almost certainly have allowed Thaksin to return from exile in exchange for the immunity of Democrat politicians and military leaders responsible for the murderous military repression in 2010.

Not all Red Shirts were happy with this, believing that the lives of those who had died in democratic protests were being traded for Thaksin's fortune and status.

Nonetheless it was among the far-right of the Yellow Shirt movement that the amnesty Bill was seen as move to restore Thaksin to power.

The far-right does not hate Thaksin for his shady business dealings, all too common among all sections of the Thai elite, nor his willingness to use brutal repression against alleged drug dealers or the Muslim Malay minority in the south.

All that could be forgiven. But what Thaksin did was to destabilise the Thai political system.

Before Thaksin, the country had a neat triangle of power, whose three sides were the monarchy, the army and the business elite.

Thaksin belonged to the new bourgeoisie that arose in the 1980s and '90s, he made his own fortune in telecoms that were not so beholden to this establishment.

Just as he had carved out a telecoms market serving the urban and rural poor who had no access to modern communications until the advent of the mobile, Thaksin targeted the same constituency with affordable health care benefiting millions of Thais.

These people have been the bedrock of the Red Shirt movement and Thaksin's and Yingluck's vehicle to the premiership.

The Red Shirts have so far curtailed their mobilisations to the tens of thousands rather than the hundreds of thousands of loyalists Yingluck could count on to defend her government.

She has also been restrained in the use of police repression, certainly in comparison with her predecessor - or her brother for that matter.

Yet the government cannot wait indefinitely and see protesters occupy ministerial buildings in a confrontational campaign of deliberate disruption.

Red Shirt organisers see little room to compromise with Suthep.

Speaking to the South China Morning Post, Tida Tawornseth, chairwoman of the United Front of Democracy against Dictatorship, the main Red Shirt umbrella group, said: "It is a crazy idea because it means that Suthep denies democracy and the rule of law.

"More than 26 million people voted in the 2011 election. How can you deny the result of an election that big?

"Suthep says he wants to get rid of the Thaksin regime, but that means throwing away the constitution."

Suthep's adventurism is also badly timed. Tomorrow is the King Bhumibol Adulyadej's birthday and in a country where reverence for the monarch is rigidly enforced, the prospect of clashes or demonstrations on that day is almost unthinkable for any royalist.

The clock is ticking for Suthep. While the protests have become more violent, they have also become smaller since the weekend. Suthep's "V-Day" seems to have come and gone.

So far the army has not moved in his favour and no military coup has lasted more than a few days in Thailand without the support of the king.

For the royalist right, more worrying from a longer-term perspective is that Bhumibol will be 86 on his birthday and he has been in poor health for years.

The succession will bring to the throne his deeply unpopular son Crown Prince Vajiralongkorn, whose colourful private life has been a constant source of prurient interest to ordinary Thais and of mortified disapproval from royalists who revere Bhumibol's austere aloofness.

The royalists will only be able to play the king's card for a short while longer. And for now Yingluck seems intent on calling Suthep's bluff.