Students march on Westminster in a last-ditch protest against the proposals

For a few hours yesterday Nick Brown achieved the impossible. He became more unpopular with students than Tony Blair.

As hundreds marched on Westminster in a last-ditch attempt to convince MPs to vote against the introduction of variable top-up fees, reports of the rebel leader's 11th hour defection were met with anger and cynicism.

"Who's Nick Brown? Who cares?" they chanted as they wended their way through the streets of London.

"He's just a traitor. If we have to wonder how they are going to vote, then the party no longer represents working-class people," said Dan Mayer. For the 20-year-old maths student yesterday was the culmination of a long journey of protest.

Along with several others from King's College, Cambridge, he began his march on Saturday afternoon, relying on the kindness of a local vicar and other universities to bed down for the night.

"Cambridge has always had a bad record on working-class access. This will make it worse. Cambridge will just have the cream of society - rich, thick and full of clots," he said.

For many students, plans to allow universities to charge up to £3,000 in top-up fees represented the ultimate betrayal by a Labour Party which had promised the exact opposite in its election manifesto.

"We are here to put some backbone into the Labour backbenchers," said Sam Caldwell. "Every single year at the Labour Party conference they sing, 'When cowards flinch and traitors sneer, we will keep the red flag flying here'."

"It is complete hypocrisy. They have totally sold out over working-class issues. This is the final straw and it's time the backbenchers draw a line," added the 19-year-old history student.

While Mr Blair's allies were working hard to avoid a defeat over the Higher Education Bill yesterday, his case already appeared lost among the students.

James Meadway said: "A lot of people were annoyed that Labour MPs were prepared to back the Government over the war in Iraq. That cynicism has filtered through. No one is surprised at Nick Brown's defection.''

The 24-year old, who is doing a PhD at the London School of Economics, added: "A lot of people are sick to the back teeth of them and what they have done over the past few years. Why spend billions on a war and then turn round and say to students there is nothing for universities?"

Whereas accusations of "Tory bastard" might once have been levelled at Margaret Thatcher, yesterday it was an insult which was aimed at Mr Blair. Nevertheless the atmosphere was jovial and high spirited as the students set off.

"Bring back, bring back, bring back my grant cheque," they sang as they went down the Strand. Only a couple of joggers, who called out: "Get a job, you wasters" appeared to object to the gathering.

The mood turned nasty as some of the students began a sit-in on the roads around Parliament Square. Scuffles broke out with police and one man was arrested for a public order offence. But essentially the march passed off peacefully, most choosing to make their mark through the democratic process.

Mandy Telford, president of the National Union of Students, was among dozens who filled the central lobby waiting to see their MP. The Union, which helped to organise yesterday's march, said that 16,047 students had already written to their parliamentary representative through its Stop Fees Now website.

Yesterday, as she waited to see her MP Barbara Roche (Hornsey and Wood Green), who was expected to rebel against the Bill, Ms Telford said: "This is our last chance to convince backbench MPs to vote against the Bill."