At the home of the soap-box, there is a lot of froth but little substance

With a belief so strong that it nearly toppled him off his step-ladder, the man at Speaker's Corner revealed the cause of Osama bin Laden's success: "Aliens. They body-snatched the 11 September hijackers."

The crowd listening to the man, whose repertoire of al-Qa'ida activists also included "all gays and Russians", tutted briefly before exiting en masse to leave the soapbox prophet addressing some pigeons.

Around him, the remaining half-dozen voices addressed a crowd of about 200 bemused tourists on the edge of Hyde Park about the need for the air strikes to stop immediately.

But there was little sign that the bombing campaign had sparked a revival of the impassioned debates of the 19th century or 1960s – when Speaker's Corner was turned into a seedbed for the forces of dissent.

Indeed, those attending London's arena of free speech yesterday in the hope of hearing the nation's finest firebrands could not have been blamed for thinking the lunatics had taken over the asylum.

Where once there stood the likes of Karl Marx, Vladimir Ilyich Lenin, Lord Soper or Tariq Ali, the debating space was dominated by Bible-waving evangelists giving their take on the Afghan crisis.

One man, wearing a Palestinian headscarf and a T-shirt emblazoned with "Jesus", said: "Allah has brought nothing but misery to the Middle East and it must stop. Embrace Jesus and end the war."

Only in the quieter edges of Speaker's Corner could the better-argued points of view be heard.

One man, admittedly clad in a face mask fashioned from a tin can and egg carton, said: "War doesn't only lead to the death of innocent people, it robs us of our freedoms. With war, disappears our freedom of speech, our freedom of movement, our freedom to trade. We must be questioning of the motives of all concerned – the Taliban, the Americans, the British."

Another speaker, who stood on a podium with the slogan OneWorld, explained patiently that only with a reformed and strengthened United Nations could governments head off global conflicts.

Just 15 feet to his left, Aaron, a Birmingham-born Jew, told his audience of about five people: "I'm Jewish and I'm ashamed of what Israel is doing. I believe that what they are doing to the Palestinians contains elements of what the Nazis did to the Jews. The Palestinian issue is at the root of the entire problem. Nothing changes until it is solved."

The Arab-Israeli conflict was not the only disappointment for Aaron, who had been coming to Speaker's Corner since 1992. He said: "It used to all be about politics here but now it's all religion. The quality has definitely dropped. After 11 September, we don't even get as many tourists."

And interestingly, in a corner of England renowned for its openness, there seemed to be a distinct edginess.

One speaker who, earlier in the day, had been calling on the Allies to print full proof that Osama bin Laden was behind the attacks on America "in the spirit of a free society", refused to give his name.

When approached by The Independent and shown a press card, he said: "How do I know you're not from MI5? I heard they have microphones here that feed straight into their headquarters."