Stop the Cuts - National Demonstration

Met Police explanation as posted on the Guardian site:

http://www.guardian.co.uk/education/blog/2010/nov/30/student-protests-live-coverage

2.56pm:
The Metropolitan police have said the line of officers that formed across Whitehall this afternoon was not an attempt to contain protesters.
A statement on their website appears to be aimed at addressing some protesters' fears that they were going to be 'kettled' on Whitehall. Many protesters began marching down the street earlier this afternoon, but upon seeing a line of "hundreds" of police barring their way they turned and ran, causing the fragmented groups of protesters we are now seeing.
[INDENT]The Met police worked with organisers in advance to agree a suitable route from Trafalgar Square down to Parliament Square for a peaceful protest.
However, today's march set off at an earlier time than agreed. This meant that the march began without a police escort. The police escort was essential due to gas main works on one side of Whitehall.
As a result, a line of police officers formed a cordon across Whitehall. This line of police officers intended to steer the march to one side of the road and the agreed route. There was never any intention to contain the protesters.
The march then broke into small groups, travelling in different directions.
The march continues peacefully, however, it is causing some disruption for Londoners in the West End, in what are already difficult conditions due to the weather.
[/INDENT]I'll be speaking to Simon Hardy, one of the people behind the London demonstration, shortly to get his perspective on whether the march set off earlier than planned.