Students attack the Conservative Party headquarters building and ignite a bonfire as the peaceful rally against a rise in tuition fees turns violent. Channel 4 News is at the protest.

Students smashed windows at a protest in London against tuition fees (Getty).

Politicians in the eighteenth century regarded violent attacks as an occupational hazard. They would expect to be hauled out of their carriages and pummelled to the ground by the masses - or so said my history lecturer.

Tell that to the cowering receptionist at Tory HQ we saw manning the desk alone as clashes broke out at the "biggest student demo in generations" over student fees.

Students attacked the building, smashed windows and barricaded the main entrance with burnt placards emblazoned with, among other things, "Liar Liar, Nick Clegg's on fire".

With not an MP in sight, Tory office workers were held hostage upstairs in Millbank Towers, taunted with chants of "Tory scum", as students ignited a bonfire in the main concourse in their protest against a hike in tuition fees.

Unprecedented turnout

It was an ugly turn to an otherwise largely peaceful march. A jubilant Aaron Porter, National Union of Students (NUS) President, had told Channel 4 News just ten minutes earlier that the turnout of around 50,000 was unprecedented.

Indeed, students from as far as Scotland, Wales and Cornwall spilled out of coaches, train and tube stations this morning – bringing Westminster and beyond grinding to a halt.

This is the start of a much bigger campaign. The politicians will feel it spread to their seats - to their constituencies. NUS President Aaron Porter.

And we are to expect more, Mr Porter said.

"This is the start of a much bigger campaign. The politicians will feel it spread to their seats – to their constituencies," he said.

This was strikingly evident from the number of non-students involved in the march. Like us, Labour MP David Lammy said he had bumped into grandparents and parents marching against government cuts.

Students broke into the Conservative party headquarters at Millbank Tower, London

Pensioners and students shoulder-to-shoulder

At the forefront of the march, pensioners stood shoulder-to-shoulder with students.

As Janet Shapiro from the National Pensioners Convention held a vast banner aloft, she told Channel 4 News: "We're here because we believe education should be free, funded by the taxpayer. It is something that benefits the community, the country. Young people shouldn't start life with large debts that are worse than mortgages."

Frances O'Grady, Deputy General Secretary of the Trades Union Congress (TUC), sparked one of the biggest roars of support during her speech outside the Tate Britain gallery.

"Don't you dare tell us we're all in this together," she said. "The deficit certainly wasn't caused by the students."

Calling for the bankers and financiers to be held to account, she added: "When the Lib Dems come looking for our votes, they had better take a good hard look in the mirror first."

Don't you dare tell us we're all in this together. The deficit certainly wasn't caused by the students. Frances O'Grady, Deputy General Secretary of the Trades Union Congress.

Mr Clegg – whose own home was subject to a student vigil last night – suffered the most vitriolic abuse from the crowd. His face was the first to appear, on the first video, screened on a massive plasma TV above the crowd. Introduced by the University and College Union general secretary Sally Hunt, the video ran through a string of broken promises from the Lib Dems.

'We didn't come here to cause trouble'

Students Anouk Chalmers and Clara McCullagh were part of a 500-strong team from Kent University who had boarded coaches at 9am to join the march. Miss McCullagh told Channel 4 News: "The politics doesn't surprise me anymore, and we might not even be affected by the cuts as second year students. But my siblings might be, and my cousins – they’re clever but they can’t afford £9,000 fees."

Both were among the rabble as the violence broke out at Millbank Tower.

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Miss Chalmers said: "It was uncalled for, it has given the demo a bad name - we didn't come here to cause trouble."

Jonross Swaby, a student at City University London, told Channel 4 News: "I'm completely in favour of the demo but not what it's descended into.

"There seem to be a lot of confusion about the protest route and some students ended up near the Tory HQ. Stewards started pushing people along and this whipped a small crowd of students up which got bigger.

"It got really scary. At one point there was a loud bang and we could see smoke, we didn't know what it was."

A group of graduate artists from Camberwell said they were marching to show their "distaste and support" for the sake of future students. Capturing the earlier spirit and good humour of the crowd, the four men had donned loincloths and carried a fifth friend, also sparsely dressed, on a wooden cross.

When the first protestors arrived at Tate Britain in the early afternoon, gallery goers were happily eating their sandwiches outside, unconcerned, safe.

The ensuing violence visibly shook up Mr Porter, who told Channel 4 News later on: "I completely condemn the violence, the act of a minority in a peaceful protest. If this undermines our case it has been utterly counterproductive. There is no justification for violence and the law being broken."

Students outflank the police
It seems pretty clear that the students have done their homework outflanking the police in reaching Millbank tower on London's embankment - before the police did, writes Channel 4 News Chief Correspondent Alex Thomson at the protests.

So it is that tonight plenty of windows have been smashed, graffiti such as Tory scum, Tory pigs, anarchy symbols and a large ejaculating penis have been daubed on a London office block. No doubt the Police Federation will be using this to lobby for more funding – just like the students have.

As I speak they are already sweeping the streets clean. They have even boarded up some of the windows already. At least 20,000 students marched today, and the violence, of course was caused by a minority. But what these students are too young to remember is that sometimes violent protest is a very effective way of changing the way things are.

These students will not remember the Trafalgar Square poll tax riot, which was instrumental in ending not just the poll tax but Margaret Thatcher’s time in power altogether.

Bearing that in mind those like the NUF who are protesting at a relatively small amount of trouble might do well to bear the poll tax precedence in mind.
#demo2010 sparks debate on the Twittersphere
@karnag Wonder if David Cameron has been getting any tips on how to deal with Millbank protests from his new friends in China?
@TSRoake Tomorrow we'll remember the millions of people who gave their lives so these students could be free to behave like animals. #Demo2010
@Tim_Aker Why are there so few police there? That's the cut people should be protesting about #demo2010
@m_neko I wonder if the people b**ching about how we're supposed to be at lectures realise that our lecturers are protesting too.
@SuzyFerg @channel4news it may well be but actions like this are not getting them any sympathy http://ow.ly/i/5mro
@s8mb @channel4news When you point out that rioters are a minority among marchers, also point out that marchers are a minority among students.
For more on Twitter go to http://twitter.com/channel4news or search the hashtag #demo2010