Internet activism is spelling the end for the age of spin, the online campaign guru Joe Trippi will warned two British politicians, suggesting that the rules for dealing with "old media" no longer apply.

"The game has changed in a way the top needs to understand," he told the Guardian.

"It may take a disaster: a leader saying something ridiculous in an unregulated moment, thinking no press are there, and then realising a person in the UK with a video cellphone could destroy you, [with the clip] getting passed through social networks.
"Before TV, what mattered was how your voice sounded. Then with TV it matters what your candidate looks like ... Anybody can fake it on TV: all the Joe Trippis and Alastair Campbells get really good at making sure our guy looks great for the eight seconds that are actually going on the news.

"We are now moving to a medium where authenticity is king, from what things look like to what's real ... You have to be 'on' 24 hours a day, seven days a week."

Tony Blair recently attacked the mainstream media as a "feral beast" which requires new regulation and lamented his lack of success in bypassing it through websites and press conferences.

But Mr Trippi believes the influence of the established media is waning and argues that politicians must allow activists to build their own online communities, not simply use the net to disseminate information.

He argues that, in an age of declining deference and empowered individuals, most voters will trust the opinion of peers who endorse a politician much more than a "top-down" message.

Rather than encouraging politicians to say one thing in public and another in private, this shift makes it pointless for them to try.

Platitudes will simply bore people, but the public will learn to filter out trivial gaffes: voters are unlikely to tolerate evidence of racism, but may learn to accept that senators occasionally drop off in hearings, for example.

But the switch will be particularly hard for incumbents, he suggested, who have to abandon the tactics which have made them successful.

"Parties that have had iron-clad message discipline -- in the US, the Republican party and in the UK, Labour -- have a tougher time," he warned.

"Command and control ... [is] a disaster in the peer-to-peer social network world."

Mr Trippi addressed Members of Parliament and other campaigners on the changing face of politics at a meeting in Westminster organised by the social networking group Bebo.

He was hailed as the man who reinvented campaigning after using the net to build an unprecedented grassroots movement around Howard Dean's bid for the 2004 presidential nomination: creating an official blog, raising huge amounts in small donations and using Meetup and other social networks to allow volunteers to organise themselves.

"The candidate lost, but the campaign won," argued Mr Trippi, who has now joined the John Edwards campaign.

"Most people think: 'My £10, or my four hours in my neighbourhood, can't make a hill of beans in this big mess of politics.'

"They come to realise that if 300,000 people put in £10 [or their time] we can change the whole country."

Labour's deputy leadership candidates have begun to learn his lessons -- Jon Cruddas has posted videos on YouTube; Alan Johnson is updating supporters on his whereabouts via Twitter -- but Mr Trippi suggested that the UK faces particular challenges.

Set election dates in the US make it easier to build momentum in the run-up to polling day.

"What I see happening [here] is people saying, 'Let's try this on the net,' when the election is going to be in 60 days.
"Then [they just assume] it doesn't work like it does in the States. The party that pushes through that and understands that the future is bottom-up and that continues through false starts will be the party that destroys other parties over the long haul.

"The parties are also stronger here organizationally; they're top-down [from the leader] ... There's almost a feeling that 'we don't need riff-raff telling us what to do'."

Mr Trippi argued that the parties had to learn to utilise the networks created by supporters, rather than corralling activists into party structures.

"Social networking is building an army of Davids. You don't want to be Goliath. So how does Labour or the Conservatives provide slingshots for the armies out there who want to do something on climate change?" he asked.

"What happens if the president of the EU tells US citizens to go sign the Kyoto treaty for themselves and 20m Americans do? It would have no legal standing -- but what does the president of the US do?"