Police threats to use rubber bullets if violence erupts at a national march have made it more likely that trouble will occur, organisers said.
Around 10,000 university and college students are due to descend on London to voice their anger over Government funding cuts and plans to triple tuition fees.
The demonstration comes exactly a year after thousands of people first took to the streets to protest against the Government's higher education plans. Those protests descended into chaos, with violent clashes erupting between police officers and troublemakers who hijacked the marches, leading to hundreds of arrests.
Amid fears that those scenes could be repeated, Scotland Yard announced on Monday that baton rounds, or rubber bullets, will be made available for police chiefs to use if necessary.
But Michael Chessum, lead organiser of the demonstration, accused police chiefs of acting in a "political and cynical" manner. "What the police have done is extremely political and a cynical attempt to put people off from coming to a national demonstration," he said. "What they are doing is trying to put people off and pre-criminalising the process. They are ramping up the pressure and in the process being completely irresponsible."
Mr Chessum added: "They have made it more likely that trouble will occur."
A day of local action is also planned for November 23, Mr Chessum said.
Scotland Yard Commander Simon Pountain said on Monday that around 4,000 officers will be on duty thanks to aid provided by other forces. "We know the overwhelming majority of students are law abiding and we hope this will be a peaceful event," the police chief said.
"We certainly don't see it as inevitable that we will witness a repeat of last year's scenes of violence and criminal damage. However, it would be negligent if we did not plan a response to the small minority who may be intent on disruption and may not intend to be peaceful."
Regarding the potential use of baton rounds, a police spokesman said: "There are a range of tactics available if there is criminality and violence associated with the event. One of these is the authority to deploy baton rounds in extreme circumstances. These are carried by a small number of trained officers and are not held and used by those officers policing the route on Wednesday."