By Max Clarke

At least 20,000 students have once again taken to the streets in the latest protest against the university fee rises.

MPs are preparing to cast the divisive vote today, at 5pm, that threatens to cleave a schism within the coalition government, and to alienate large numbers of students from politics.

The incensed crowd in Parliament Square once again reached flashpoint, with missiles once again hurkled at the police as they attempted to enforce order.

A small number of protesters infiltrated the Commons public gallery, where they stood up during the proceedings and shouted, before promptly being ejected by doorkeepers to jubilant applause from many of the viewers. Their attempts at subversion, however, went largely unnoticed by the MPs below due to the plate glass window separating the two groups.

At least one police officer has been seriously injured, and it is not known how many protesters have been hurt in the rioting that has lasted much of the day and continues to rage.

Smoke bombs and flares were once again set off, as lines of armoured riot police attempted to stop the crowds from breaching their lines and storming Parliament.