By Frank Gardner BBC Middle East Correspondent

As the Saudi-born dissident Osama Bin Laden's latest broadcast denounces Muslims who support the US strikes on Afghanistan - such as the Saudi Government - many ordinary Saudis remain loyal to their home-grown idol.

British Prime Minister Tony Blair's recent visit to Saudi Arabia sought to bolster Riyadh's backing for the military operation, but it failed to win over most of the Saudi public.

Blair's visit made little impact on ordinary Saudis

The Saudi Government is quietly helping the West to combat Osama Bin Laden and his Al-Qaeda organisation, but many ordinary Saudis see Bin Laden as a hero who shares their beliefs.

At Friday prayers in the town of Buraida - the heartland of Wahhabism, which is the ultra conservative Saudi brand of Islam - nearly all the men listening to this sermon are either supporters of Bin Laden or else government informers.

It's a tense place where everyone looks over their shoulders. One man here, Abdullah, is one of the few who dared talk to a journalist.

Willing audience

He says Bin Laden's messages of hatred of Western policies have found a ready audience amongst ordinary Saudis.

"Of course everybody here is against the West, because of its stance with Israel against the Palestinians, and against Iraq for more than 10 years, and now in the campaign in Afghanistan, and all the civilian casualties there."

He also criticised the presence of US troops on the Arabian Peninsula, arguing that Saudis want to defend their land, not have Americans do it.

In the privacy of their own homes, some Saudis like Abdullah are using their computers to log onto internet audio chatrooms in Arabic.

Cyber dissent

Using websites run from outside the country, they talk about topics forbidden at home - criticism of the ruling family, hatred of US forces based here in Saudi Arabia.

One website shows a photo of a US warplane in the desert. The caption reads: Pray to God that it crashes.

Interrupting an online discussion in Arabic, I asked one of the anonymous chatroom correspondents to say what he thought about Bin Laden.

Like so many people here in the Gulf, his answer showed he still did not believe that Bin Laden was behind the World Trade Center attacks.

US troops are unpopular on Saudi soil

"We support him because he's our son, he's one of us. He belongs to us and he's supporting our religion. So you want us to support George Bush - who's supporting Israel and hitting us? Israel's hurting Muslims and killing innocent people and you think that's not terrorism?

"OK, so what about Osama Bin Laden? He didn't kill innocent people. How do you know that he's the one who blew up the Twin Towers?"

On the streets of Riyadh and other Saudi cities there is no public sign of support for Bin Laden.

The government has forbidden it. So if his popularity is all in people's minds here, can they be swayed by the arguments of someone like Mr Blair?

Blair's tough task

The London-based Saudi dissident, Dr Saad Al-Faqih from the Movement for Islamic Reform in Arabia, thinks not.

"If we talk about people, not the regime, people have already made up their minds that Blair is an ambassador of America. So whatever he says they will not give a damn, they will always be so sceptical that they will explain it against him."

He explained this meant there would be "no chance of convincing people of any sort of a statement by Tony Blair".

Depressing words for the British leader, as he presses on this week with his campaign to bolster support for the war against terror.

Despite his best efforts, it is a campaign that has so far failed to win over all but a fraction of Arab public opinion.