David Dimbleby was joined by president of the Stop The War Coalition Tony Benn, chairman of the Conservative Party Francis Maude, Liberal Democrat Treasury spokesperson Julia Goldsworthy, Russian billionaire Boris Berezovsky and Daily Mail writer and columnist Melanie Phillips.

TONY BENN

Career: Tony Benn was the longest serving MP in the history of the Labour party, holding posts in the cabinets of Harold Wilson and James Callaghan.

Since retiring from the House of Commons in May 2001 to "devote more time to politics", he has been a leading figure in the British opposition to the Iraq war, which he describes as "an act of criminal aggression", and is president of the Stop The War Coalition.

A BBC Daily Politics Show poll in January 2007 selected Benn as the UK's "political hero", narrowly beating Baroness Thatcher.

FRANCIS MAUDE

Career: Francis Maude is chairman of the Conservative Party.

He was shadow chancellor of the exchequer from June 1998 until February 2000 and shadow foreign secretary from February 2000 to September 2001.

He was also a Foreign Office minister in the last Conservative government.

Writing in the Telegraph after the 2005 election defeat, he urged the party to be "more successful at expressing the aspirations of modern Britain", suggesting that Conservatives "too often ...look and sound as though we regard the modern world as an aberration and look forward to the restoration of a lost golden age."

JULIA GOLDSWORTHY

Career: Julia Goldsworthy is the Liberal Democrat Treasury spokesperson.

Winning the seat of Falmouth and Camborne in the 2005 election, she became the youngest MP in the House of Commons, and was appointed a party spokesperson on health in the same year.

She remains the youngest member of the Liberal Democrat front bench. Last year, she competed in the Channel 4 series The Games, finishing as runner-up.

BORIS BEREZOVSKY

Career: Boris Berezovsky is a Russian billionaire, and was one of the most powerful men in Russia under Boris Yeltsin. He now lives in exile in the UK.

He made his fortune, along with the other Russian "oligarchs", buying up Russia's industrial assets during the turmoil of the post-Soviet years.

He became deputy secretary of Russia's Security Council and was a close political ally of President Yeltsin, going on to fund the party that formed the electoral base of his successor, Vladimir Putin. However, after his initial support, he has become an outspoken critic of President Putin, and moved to London in 2000 following Putin's election victory.

He is a former employer of the ex-KGB agent Alexander Litvinenko, who died in London last November after being poisoned by the radioactive substance Polonium 210.

MELANIE PHILLIPS

Career: Melanie Phillips is a writer and columnist for the Daily Mail.

She worked at the Guardian for more than a decade, where she became a columnist after a brief period as news editor. After a short time at the Observer, she joined the Daily Mail in 2001, where she now writes a controversial column on moral and social issues.