Friction.TV, the video-sharing site aimed at Britain's "activist population" that bills itself as a "virtual speakers' corner", has attracted 250,000 users since it launched three months ago - more than YouTube, the web's most popular video site achieved at the equivalent stage of development.

Billed as a "YouTube for grown-ups", Friction's founders have said that the site is aimed at viewers more likely to write to a newspaper to voice their frustrations - over issues such as the environment, planning regulations and Iraq - than to join an online social network.

It allows users to upload videos of themselves discussing national, international or local issues on to the web. The site, which moves out of its beta - or test - phase today, was founded by Omer Shaikh, the former head of the Saatchi & Saatchi digital media agency Red Kite, and Andy West, a former PR executive at Text-100.

Contributors to the open, unedited platform, which has launched a PR campaign targeting "popular culture influencers and opinion formers", include Boris Johnson, the celebrity Conservative MP and Nick Griffin, the leader of the BNP.

Advertisers have included Vodafone, the telecoms group, and Samsung, the Korean electronics giant.

The site's featured "hot debates" have ranged from complaints by St Ives locals on how there are too many arts galleries in their town to discussions on why "bombing Iran would be disastrous".

"Friction.TV was founded to provide an antidote to mainstream media by delivering challenging, and sometimes raw, opinion from all sections of society," Mr West said.

"The site is founded on a belief that everyone has a right to voice an opinion no matter what it is … It basically provides the public with a 21st century soapbox."

Unlike YouTube, which was bought by Google for $1.6 billion last year and leaves contributors to their own devices, Friction, which has raised more than £1 million in seed funding, uses "assisted user-generated content". That means that teams of university students and other freelance contributors around the country are paid to take cameras to the streets to field public opinion.

The site is "viewer moderated" and any inappropriate content that "crosses the boundaries of decency or that contravenes any law" is removed.

It plans to make money through advertising, content syndication and the sponsorship of various debates and hopes to average one million users a month by the end of the year. The founders have also said they hope to place video booths, described as "upmarket equivalents of the Big Brother diary room", across the UK.

Mr West said: "We initially wanted to test the idea of Friction.TV by seeding it publicly through word of mouth.

"The response has been fantastic with viewers clearly welcoming the opportunity to voice opinions in an uncensored, easy accessible way. Our aim now is to encourage as many people as possible to have their say on issues they are passionate about."

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