The Police were hopelessly outnumbered so could do little except stand and watch. They called in reinforcements from just about everywhere including City of London, British Transport Police and local Westminster duty plods. Having no option but to adopt a softly, softly approach they kept well back letting the stewards gently move the protesters back into the square. They then formed a line of vans and officers across the front of the demo and remained until the protest finished. There was no violence, the protest remained loud and angry until the end.
Expect greater numbers on Saturday.