The announcement, carried live on national television on the evening of Republic Day after violent protests in towns and cities around the country, was swift and dramatic.
But for close watchers of Tunisia, it was the culmination of several years' worth of strategic moves on the part of Mr Saied to consolidate power and reshape a country controlled by Islamists for much of the last decade.
Mr Saied, a constitutional law professor without a political party, swept into power in 2019 on a wave of populist fervour.
Tunisians across ideologies, geography and class found his anti-politician persona – stiff, formal, laser focused on corruption – a refreshing antidote to slick and polished career politicians whom he said he wanted to hold accountable for their mismanagement of the government and economy.
In his campaign he preached law and order, and pressed for an end to immunity for parliamentarians whom he considered corrupt.
“Even since the campaign trail he has been saying he doesn’t believe in parliaments,” said Sarah Yerkes, a senior fellow at Carnegie’s Middle East programme.
His message resonated with a population exhausted by eight years of political dysfunction after the 2011 revolution, and Mr Saied sailed into office with 72 per cent of the vote.
Yet, early on, “there were warning signs” that Mr Saied was slowly trying to wrest power away from Parliament and consolidate it around the presidency, said Said Benarbia, the director of the International Centre for Jurists’ Mena programme.
When his first prime minister, Elyes Fakhfakh, was embroiled in a financial scandal, Mr Saied forced his resignation before a vote of no confidence could be taken and put forward his own candidate, Hichem Mechichi, who was interior minister at the time.
The move was seen as a way to break down the party system and install loyal technocrats able to steer the economy and government.
Tunisia has struggled to get its economy moving since the 2011 revolution but the Covid-19 pandemic has hit hard. Unemployment, which stood at 14.9 per cent before the pandemic, was at 17.4 per cent by the end of 2020, according to the World Bank.
Talks with the International Monetary Fund for a major loan package stalled earlier this year.
In January, Mr Saied refused to swear in several ministers Mr Mechichi had appointed in a cabinet reshuffle, claiming each had conflicts of interest. And in a speech commemorating the 65th anniversary of Tunisia's independence in April, Mr Saied made a move to consolidate both the military and civilian armed forces under his supervision, despite a clear separation of the two in the constitution.
"The president is the supreme commander of the military and civilian armed forces. Let this matter be clear to all Tunisians," he said in his speech, which was attended by both Mr Mechichi and Speaker of Parliament Rachid Ghannouchi, the leader of the Islamist Ennahda party and another of Mr Saied's key rivals.
The consolidation of the security forces strengthened Mr Saied's image among supporters as a law and order politician but concerned civil society as Tunisians saw what Ms Yerkes called a "worrying" sharp increase in police violence and impunity.
In recent months, Mr Saied’s populist, man-of-the-people persona has evolved and a new stubborn intransigence emerged as he refused to negotiate with those he viewed as rivals.
One major point of contention, the Constitutional Court, is at the heart of the current crisis. The 2014 constitution called for the creation of the court to act as a check and balance against the other branches of government.
It would comprise a 12-judge panel, with four justices each appointed by the president, the parliament and the High Judicial Panel.
“The role of the constitutional court is to ensure that each authority is exercising its power within the boundaries of the constitution,” said the ICJ’s Mr Benarbia.
For about eight years, a factionalised parliament, led by the Islamist Ennahda party, has failed to put forward enough judicial candidates who could secure a three-fifths majority vote of approval.
In a crucial step earlier this year, Mr Saied refused to sign a law lowering the threshold, claiming the court legally should have been formed before a 2016 deadline set out in the constitution.
The move effectively blocked the formation of the court – and the check on the presidency's consolidation of power.
“In the absence of that arbiter that regulates the work of public authorities, the president saw an opening to say ‘our interpretation of the constitution is the correct one’,” said Mr Benarbia.
Ms Yerkes said there has been an expectation that something like this would happen for several months, "that either Saied or Mechichi would have to do something drastic to end the political chaos”.
She said that moment came this week after public outcry over the handling of the latest surge of the pandemic which raised the death toll to more than 18,000 in a nation of 12 million.
A botched vaccine drive resulted in thousands of Tunisians waiting for hours in the sun in thick crowds, scrambling for jabs at walk-in clinics which ran out of doses within hours of opening.
Mr Saied called Mr Mechichi's actions "criminal," and promptly put the vaccination drive under the purview of the military. Days later he leveraged the country's outrage to oust Mr Mechichi as he froze Parliament.
Without the constitutional court in place, opponents of Mr Saied may have few options to regain control of the government.
"Saied has said he can extend the Parliamentary freeze beyond 30 days, and we don't know how long he could extend it for," said Mr Benarbia.
Mr Saied has ordered the army and security forces to block the entrance to parliament to keep politicians from meeting. Mr Ghannouchi spent Sunday night at a sit-in outside the parliament gates.
Eya Jrad, a Tunisian professor of political science and law, said another obscure article of the constitution may provide a loophole.
“Parliament itself could convene in a different place rather than the Bardo and vote to withdraw confidence from Kais Saied,” she said. The vote would require a two-thirds majority.
Despite the uncertainty, Mr Saied still has the support of hundreds of thousands of Tunisians, many of whom are eager to see the dissolution of a dysfunctional parliament and, with it, the downfall of the Islamist Ennahda, Parliament’s largest party.
Ouiem Chettaoui, a Tunisian public policy specialist, said that Mr Saied supporters may be willing to sacrifice a little freedom for stability.
"I don't think there is an ignorance of the fact that what was done was not completely within the framework of the constitution," she said.
"But it is still unclear if that is because people believed in Kais Saied – that he does not want a dictatorship, that he wants popular democracy and localised governance – or because something had to give."
As Tunisian’s poured into the streets to celebrate late into the night, shouts of “Down with Ghannouchi!” echoed across the crowd.
Among them, 28-year-old Imtissar reflected on the brusque power play.
“Because of the way Saied used the constitution, this is not a complete defeat of Ennahda, but rather a restraint. We need to organise ourselves for what is coming next.”