Hundreds of student protesters have smashed through police barriers and flooded onto Parliament Square, The Telegraph reported on Wednesday.
They pushed through a roadside barrier, dodged police and tore down a second set of metal barriers to gain access to the square.
Many of the protesters who broke down the barriers were dressed in black with their hoods up and red flares were set off outside the Houses of Parliament.
Initially four or five policeman tried to stop the protesters jumping over the fence but the numbers overwhelmed them.
Some protesters boasted of stealing policeman's hats and throwing them in to the crowd.