IT is not every day that I share tea and shortbread with a world-famous writer, a government minister, a leading actress and a recently-defected MP, but that's what happened on the Friday before Christmas.

I arrived in plenty of time at Marlborough Road Methodist Church, St Albans, for the recording of the BBC Radio Four discussion programme Any Questions, and was invited by minister Martin Caldwell to wait in the back room prepared for the panel.

The only member to have arrived was Mr Paul Marsden, his face instantly recognisable it had been on the front pages of the national papers only about a week before when he announced his defection from Labour to the Liberal Democrats.

As I stirred the teapot, he told me about his welcome into his new party, and his disgust at the tactics of the Labour whips who he felt had bullied him over his opposition to the war in Afghanistan.

Hoping for a big scoop, I asked Mr Marsden how well he knew Kerry Pollard, who had joined him in a vote against the Government only days before the defection, but I was disappointed to hear they were not close allies.

I was on my second piece of shortbread when the other three panellists entered together minister for international development Hilary Benn, thriller writer Frederick Forsyth, and actress Fiona Shaw.

Although I had never seen a picture of Mr Benn, who greeted his former Labour colleague rather awkwardly, his features were instantly familiar. Not only his face but his voice and mannerisms recall his father, Tony Benn, one of the most famous characters of the British political scene of the past 50 years.

Ms Shaw's was a face I had seen several times on the London stage, as well as on television she has been described as Britain's foremost classical actress. She exchanged small talk in her distinctive Cork accent with Mr Forsyth, who, it transpired, lives almost locally near Essendon.

We were joined by the presenter, Mr Nick Clark, whose voice if not his face, was also familiar I had listened to him presenting The World at One on Radio Four that lunchtime.

I took my seat in the second pew just behind the questioners as the producer, Ms Lisa Jenkinson, was warming up the audience and checking the sound system.

The panel took their seats to applause. We listened to the 8pm news, and then we were live.

The first question, from Ms Anne Scorer, was about the £28 million air traffic control system for Tanzania the Government had just announced export credits for.

Mr Marsden and Ms Shaw were strongly critical, Mr Benn, as a minister in the department responsible, was cagey, and Mr Forsyth was in favour.

Next Mr David Connell asked whether the Prime Minister should disclose whether his baby son has had the controversial MMR vaccine, which has been linked to autism.

Mr Forsyth and Ms Shaw agreed he should, but Mr Benn said: "His children have the same right to medical privacy as all of us." Mr Marsden agreed, although he said he was quite happy to disclose his own two sons had had the triple vaccine.

A question from Mr Philip Webster about whether MPs who change parties should resign their seats, clearly directed at Mr Marsden, was answered first by the maverick MP for Shrewsbury, who said that if people wished to change the constitution, they should join his new party, which was committed to doing so.

Mr Benn said: "I am sorry that Paul left. Others seem to be able to continue to express their views but still be members of the Labour Party."

Mr Forsyth argued that the split was a symptom of the authoritarian nature of the Government, and Ms Shaw said: "He has taken a new role I wonder if he finds the new words more difficult?"

A question from Mr Geoff Brotherton about the new portrait of the Queen provoked sharp disagreement between Mr Marsden, who described it as "absolutely awful", and Ms Shaw, who said: "Lucien Freud is a fantastic painter, and we should all go and see it."

To strong applause, Mr Marsden and Mr Forsyth condemned the payment of up to £100,000 expenses to Sinn Fein MPs in response to a question from Mr Colin Gibb.

To cries of "shame", Mr Benn and Ms Shaw, who Mr Clark reminded the audience is from Ireland, disagreed.

The loudest cheer of the evening was reserved for Mr Forsyth, who spoke last on a question from Mr Ken Shuttleworth about the Government's agreement to the Europe-wide arrest warrant.

After the other panellists had praised it as a weapon in the fight against crime, he said: "I am absolutely staggered. Three mature people who have never heard of habeas corpus.

"It doesn't exist on the continent. You can be remanded in custody for three years which means the slammer."

The evening ended with a question from Mr Albert Simpson, who asked: "What is the wisest thing you ever heard?"

While the other three passed on advice from parents or grandparents, Mr Marsden quoted Mahatma Ghandi: "If you are a minority of one, it doesn't matter if you believe you are right."

The 45-minute broadcast over, Mr Clark thanked the audience for a lively contribution, and each panellist was besieged by admirers.