Of course the police would not agree to let anti-war demonstrators march down Whitehall, that is their job to act act as fascist stormtroopers. The police have always acted against the people as a fascist strike force to crush dissent from the 1926 General Strike to the 1984 Miners Strike to the 1990 Poll Tax Riot.
 http://www.londonclasswar.org

Stormtrooper........as in Vaders 501st.....Thankyou for the compliment.

Not so long ago it was the norm for protests to be allowed right outside Downing Street and throughout central London. As recently as the 1990s Reclaim the Streets / Liverpool dockers demonstration, protesters could march right up to the gates of Downing Street (before this there were no gates) and on this demo they also got inside some of the ministries. It's only recently that the totalitarian fascist/Stalinist idea that state elite spaces are out of reach to the masses has become fashionable.

“Chris Allison, Deputy Assistant Commissioner at Scotland Yard, said: "We are seriously disappointed by the irresponsible and criminal action of those who have challenged police, physically ripping apart security barriers with the sole aim of breaching security in Whitehall" (Geoff Caddick/AFP/Getty Images)”
(The Times, June 16 2008)

Also shocking (along with the usual police violence): police are whining about protesters! This was not an especially extreme demo, just some pushing and shoving, and they're talking like we hacked their heads off. They are coming out with exactly the same rhetoric as if they'd been under a hail of Molotovs. It just goes to show they will come out with this same shit whatever happens.

IT'S CALLED FREEDOM OF MOVEMENT YOU FUCKING PIG.
Standing up to police violence. “Criminal”? Not in a society which recognised basic rights. “Irresponsible”? The people are not responsible to the state! “Breaching security”? Basic rights can only come when “security” is limited by actualised rights.