Lord mayor Robert Doyle has blasted the actions of a 15-year-old schoolgirl at the centre of a rowdy Melbourne student protest, but she has drawn praise from her supporters.

University students furious at the Abbott government's planned changes to higher education burnt a copy of the budget and staged a sit-in protest outside Victoria's Parliament House, bringing the city to a standstill on Wednesday.

The teenage girl at the centre of the protest outside Parliament on Wednesday. Credit:Jane Lee

About 20 students who refused to leave the Spring Street tram tracks formed a ring around a schoolgirl who had joined them.

The girl, who identified herself as Tallulah, was dressed in her Camberwell High School uniform and was carried off the tracks by police.