Unpartisan campaigner: Alan Bennett, the rebel with a lot of causes

Alan Bennett says he has never really gone in for protests. His first, against the Suez invasion in 1956, occurred by accident when he happened to be watching it process by in Broad Street, Oxford. "Somebody just pulled me in," he recalled yesterday. "You might say I was dragooned. There was a lot of protest about the Russian invasion of Hungary at the time and the Suez left us with no moral ground. But no, I wouldn't say I've ever been a big protester. Most people when they get older get more conservative but I think I've probably gone the other way."

The playwright's whereabouts rather belied his point. He was speaking from beneath the cover of his umbrella on the windswept uppers reaches of Nidderdale in his beloved Yorkshire, where he was about to take his place on a makeshift platform to protest against the Government's tolerance of Menwith Hill - the secretive US surveillance station. A steadily increasing number of golfball radomes house electronic listening devices here, operated by the US National Security Agency.

It isn't military listening stations that Bennett disapproves of but the fact that America controls this one, rather than the Ministry of Defence. "We live in an imperfect world and although one is uneasy about it, surveillance is necessary," he told a group of 100 protesters, on the 20th American Independence Day protest against the base.

"If there's dirty work to be done, we should do our own dirty work. We don't know what goes on here. People are told it's only surveillance and this played no part in the rendition of suspects across the world for torture - but we don't know that."

Bennett had made an effort to be here to make his point. He packed sandwiches for the trip yesterday morning before setting off by train, to Harrogate via York, and then taking a taxi on to the moors, which he knows well. (He still has a cottage on the other side of Skipton from the base, which was his parents'.) But even he had to admit that his attire - trench coat, black umbrella and blue corduroy back pack - didn't quite fit in amid the Mahatma Gandhi lookalike, fancy-dress angels and the Daftasadrum percussion group who made up the zany Menwith Hill protest group. "This isn't my kind of thing," he said. "I'm more conservative, with a small 'c', than a lot of people here."

In truth the protester role is considerably less of a novelty than he might suggest. Bennett has added to that formative protest march experience in the past few years by joining several London marches against the Iraq war and could not fail to admit yesterday that he had found the experience a rewarding one. "The wonderful thing about London was that you were walking, not marching, slowly along with the WI behind and you and some anarchist group in front," he said.

The experience also proved to him that the most furtive venture into protest can have ramifications. Bennett was taken to task by John Lloyd, and called a "hysterical schoolgirl" after writing about his march experience in the London Review of Books. That hasn't stopped Bennett's protestations reaching well beyond foreign affairs - and even over Yorkshire's border with Lancashire. Another group which has successfully turned to the playwright for support over the past six months is one dedicated to halting the construction of a 360ft wind turbines on Denshaw Moor, at Saddleworth. The plans included the prospect of a windmill atop the memorably named Broadhead Noddle - a sugar loaf hill set amid the moors - which, protesters told him, would also affect vistas from deep into the Peak District National Park. Bennett was persuaded to host a £20-a-head "Evening with Alan Bennett" in a local village hall in support and his enthusiasm for the cause seems to have worked a treat. The plans were recently withdrawn.

Bennett insisted yesterday that his support for the Saddleworth campaign did not mark him out as an eco-protester. "You can't always protest. You have to get on with your he life," he said, and he will definitely be not joining London's Live Earth protest on Saturday.

Yet his determination to pursue a cause, lost or otherwise, was illustrated as far back as 1988, in his address at the memorial service for the broadcaster Russell Harty. Bennett and he had been friends since they were Oxford undergraduates together at Exeter College, with rooms on the same staircase. In the 1980s he watched the tabloid press pursue Harty, trying to "out" him as a gay man with Aids.

At the memorial service at St James's, Piccadilly, Bennett spoke of how the News of the World had set up his friend, how reporters had bribed children in the television star's village and even tried to bribe the vicar. Harty went into hospital with hepatitis. "Now as he fought for his life in hospital," said Bennett, "one newspaper took a flat opposite and had a camera with a long lens trained on the window of his ward."

When offered an honorary degree from the University of Oxford in 1999 he subsequently turned it down, because Rupert Murdoch funds a chair of language and communication at the university. "I'm aware of the arguments about bad money being put to good uses, but I still think that Murdoch is not a name with which Oxford should have associated itself," he later wrote in the LRB.

He also turned down the offer of a CBE in the 1988 Birthday Honours for services to literature on the grounds that he wanted nothing to do with an award which came from a government headed by Margaret Thatcher. And on being offered a knighthood in 1996, he refused again. "I felt that being a knight would be akin to wearing a suit every day of my life," said Bennett, who is known for his casual mode of dress.

Among the many issues that horrified Bennett about the Thatcher regime were student loans: he knew that he, and other grammar school boys, were given a future by not having to pay for university. The care of the elderly is another subject he has written on with a passion, drawing on the experience of his mother, Lilian, who was confined to a care home. "Lacking one-to-one care," Bennett wrote, "these helpless creatures slowly and quite respectably starve to death. There is something not right about homes for the elderly - not least that staff do not have the time to feed patients properly and do not notice when they are not feeding themselves.''

At the Cheltenham Literature Festival two years ago, Bennett added to his list of causes when he urged a boycott of mainstream high street retailers - naming Waterstone's and Amazon - to prevent them killing off independent bookshops. He was dismayed by the closure of his beloved Camden Town store, the Regent Bookshop, owned by Peter Bergman, which had been operating for 40 years.

At Menwith Hill yesterday, Bennett appeared to boost a cause which has returned to national prominence amid stringent national security.

Helen John and Sylvia Boyes, Yorkshire pensioners, were arrested outside the base last year under a little-noticed clause in the 2006 Serious Organised Crime and Police Act, which means protesters who breach any one of 10 military bases across Britain will be treated as potential terrorists and jailed for a year. Their case was halted in April because no one was able to tell the judge what Menwith Hill does, whether it is considered British or American territory and who runs it.

The protest experience brought its share of surprises for Bennett, who did not expect to have a Public Order Act notice thrust into his hand by police, who told him he was liable to arrest if he stepped where he should not during the protest. Neither did he expect to be videoed by officers. "They seem much more relaxed about this sort of thing in New York," he said. Bennett was not partisan: he confided that he rather liked the architecture of the golf balls, whose number has recently increased to more than 30, with a further two to be added.

But when he came to take the stage, after observing a minute's silence for "everybody affected by the illegal war in Iraq and Afghanistan" this most gentle of campaigners instinctively knew that the spy stations aesthetics were not a subject for a protest meeting. After clambering up an aluminium step ladder on to the trailer, he told a delighted crowd about how this day had brought a clash of engagements. "[Having] agreed to come here, in almost the next post I got another invitation to cocktails with the American ambassador at the embassy in Regent's Park," he said. "I didn't tell him what I was doing. I thought that would be unkind."

Additional reporting by Callum Hudson