The metal barriers came down, the sound systems pumped, and the student protesters spilled across the grass in Parliament Square.
Waves of cheering, cat-calling and chanting echoed above the drone of three circling helicopters. A tea tent, with supplies pulled out of a supermarket trolley, was set up as the protesters settled in.
Three truanting school students sat playing cards in the mud - as the politicians in the Chamber debated their future. The youths said they were cold, but glad to be there.
A group of young men, some with scarves over their mouths and one sipping from a bottle of beer, clambered on top of a metal hut next to some road works and started burning placards.
'No-one's kettling me'
Four 13-year-old girls, from Camden School for Girls, where pupils staged a sit-in yesterday, rattled the metal barriers around the work site hopefully.
They said they wanted them pulled down. One of the girls was about four feet high. They hadn't come with any adults.
"We want the MPs to hear our voices," said one of the protest organisers, as the hordes of protesters converged on Parliament Square, after a breathless scramble of a march through the pre-Christmas streets of the capital.
Once again, university and further education students, trade unionists and school pupils formed a mass below a sea of placards.
Their anger is aimed not only at the raising of tuition fees to up to £9,000, but also major cuts to university teaching budgets and the removal of education allowances for low-income 16-19 year olds.
There were youths clutching hard hats and cards with advice on what to do if they got arrested.
There were heavily made-up girls in hot pants, mini-skirts and leopard print coats, as well as protesters dressed as a Storm Trooper, Superman, and Father Christmas.
Business Secretary Vince Cable was lambasted by the protesters as a "gibbering wreck" and the Lib Dems as the "Tories' poodles".
"We will fight on! We will overcome!" The speeches went on as the protesters gathered, the organisers keen to wait until the march reached its maximum size.
"We haven't got a Clegg to stand on", read one banner. "My toilet's Clegged", said another, as the Liberal Democrat leader tries to face down his beck-bench rebellion.
But not everyone was convinced. "That's just ridiculous," commented English student Steph Dickinson, 21, from Liverpool, as one speaker called on activists to "bring down the neo-liberal state".
And then the marchers were off.
As the march started out past shoppers and tourists in Bloomsbury, police spread across the road and set a sedate pace at the front of the column of protesters. This followed the fast-paced chase for several miles around London last week.
But groups of protesters soon surged ahead and a few scuffles broke out as police tried to form new lines.
One officer was led away limping. Protester Gordon Maloney, 20, who had travelled 12 hours by coach from Aberdeen to attend the demonstration, said a policeman had punched him in the chest, and he'd seen another protester being hit with a stick.
A breakaway march poured through Covent Garden, trotting to shouts of "Whose streets? Our streets", while the main protest stayed on the agreed route along The Strand.
Harrassed-looking protest marshals in fluorescent yellow bibs shouted at protesters to slow down. One told me the aim was to hold the crowd together, at least until the march reached Parliament Square.
"Then whatever happens after that happens," he said.
And despite a few scuffles, headlong dashes and shouts of "no-one's kettling me", the crowd arrived at Parliament Square and the wait began.
And as the sun dropped, some angry clashes broke out in the shadow of Westminster Abbey.
Protesters say the police tried to move their line forward. Mounted police charged the crowd. Protesters hurled sticks from wooden placards and a chair.
A couple of fireworks cracked, while the crowd pushed forwards shouting "no ifs, not buts, no education cuts".
A young protester struggled back through the crowd with blood running down his face.
Another, Hero Austin, 20, who works for the LSE students' union, said she'd been crushed by a barrier, and police had carried on pushing as she had tried to help another protester who had been knocked to the ground.
Bonfires of placards and a park bench blazed, and then burned out.
The police stopped allowing protesters to leave. A woman pleaded to be let out to collect her child from nursery.
'Build a bonfire'
As the temperature dropped and the vote neared, a hut was set on fire. Thick clouds of black smoke billowed across the square, as the protesters sang "build a bonfire, build a bonfire, put the Tories on the top...".
The storm-trooper clambered on to the top of a hut and performed a striptease - down to the waist - in front of Big Ben. Protesters anxiously fiddled with mobile phones, waiting for word from inside the chamber.
Then it came. "The vote's passed," a woman bellowed through a loud hailer, sparking chants of "Tory scum, Tory scum".
But they were short-lived. Face to face with thick metal barriers and lines of black-clad riot police, the protesters in front of parliament seemed to be waiting for something to happen. "If someone could find the anarchists...", said one, glancing around.
"I'm gutted," said Jonathan Cotton, 20, an economics student who had travelled from Manchester. "We knew it was coming but it's still a kick in the teeth."
"I feel angry," said John Dodds, 27, from London South Bank University. "They've voted away our futures, and the futures of our brothers and sisters."
'Far from over'
But both said the closeness of the vote was testament to the power of the wave of student protest in recent weeks.
And it wasn't long before anger turned to violence in another corner of the square.
Groups of youths raised large metal barriers aloft and rushed towards the police at the entrance to Whitehall. Police charged back, with riot shields and batons.
"We're just chucking them at the police," said one. "We're trying to put them as a shield between the police and the protesters," said another. "But it's not really working, they're just coming right back at us. There's people bleeding an' everything."
And there were.
A few minutes earlier, a group had rushed back into the square carrying a young man with blood pouring from a head wound.
Someone grabbed a metal bar, and systematically smashed each pane of a window on the Treasury, to cheers from the crowd.
Elsewhere, shivering students munched bags of crisps and tubs of hummus, hovering by the police cordons in quieter corners, hoping to be allowed to leave.
Everyone vowed the protests would go on. And as the youths grabbed yet more metal barriers, it was clear the battle on the streets was far from over.