Updated

LONDON -- Tens of thousands of students marched noisily through London on Wednesday against plans to triple university tuition, and some tried to occupy the headquarters of the governing Conservative Party, in the largest street protest yet against the government's sweeping austerity measures.

Organizers said 50,000 students, lecturers and supporters were demonstrating against plans to raise the cost of studying at a university to 9,000 pounds ($14,000) a year -- three times the current rate.

Violence flared as a handful of people smashed windows in a high-rise building that houses Conservative headquarters, as others lit a bonfire of placards outside the building.

Office workers were evacuated as several dozen protesters managed to get into the lobby, chanting "Tories Out," while outside police faced off against a crowd that occasionally hurled food, soda cans and placards.

"We are destroying the building just like they are destroying our chances of affording higher education," said Corin Parkin, 20, a student at London's City University.

Organizers condemned the violence. Sally Hunt, general secretary of faculty group the University and College Union, said "the actions of a minority, out of 50,000 people, is regrettable."
Elsewhere, protesters were peaceful but determined.

"I am here because it is important that students stand up and shout about what is going on," said
Anna Tennant-Siren, a student at the University of Ulster in Coleraine, said: "Politicians don't seem to care. They should be taking money from people who earn seven-figure salaries, not from students who don't have any money."

Frances O'Grady, of the Trades Union Congress, said the hike would make colleges "no-go zones for young people from ordinary backgrounds."

"This is about turning colleges and universities from learning institutions into finishing schools for the rich," she said.

Britain's Liberal Democrats, who are part of the coalition government with the Conservatives, pledged during the country's election campaign to abolish fees.
Protest leaders said they would attempt to use recall powers to oust lawmakers who break campaign promises on the issue.

The National Union of Students said it would try to recall legislators from the party who vote in favor on the hike.

"We will not tolerate the previous generation passing on its debts to the next, nor will we pick up the bill to access a college and university education that was funded for them," said union president Aaron Porter.

While British tuition fees are modest compared to those at some U.S. colleges, British universities are public institutions. Opponents of the tuition increase have pointed out that Prime Minister David Cameron and other members of the government attended elite universities such as Oxford and Cambridge at a time when university education was free.

The previous Labour government of Prime Minister Tony Blair introduced the first fees for students soon after it was elected in 1997. Scotland abolished tuition fees in 2000, and in the rest of Britain the cost is capped at about 3,000 pounds ($4,800) a year.

Prime Minister David Cameron's government plans to triple that and cut funding to universities as it strives to slash 81 billion pounds ($128 billion) from public expenditure over the next four years.