A suitably dramatic finale to battle against developers as LA police force Hollywood stars to end protest

Only in Los Angeles could a political battle over an urban farm turn into an irresistible piece of street theatre in which Hollywood's finest perch themselves up a walnut tree and Joan Baez chimes in with a serenade of protest songs.

Only in LA, too, would the cops be unsentimental enough to break up the whole thing with unfeeling efficiency - trampling the vegetable patches and chopping down an avocado tree so the fire department could pull down the last few protesters and march them away in handcuffs.

The improbable month-long battle over the 14-acre farm, which sits in a blighted corner of South Central LA, site of the 1992 riots, came to a swift end with a 5am police raid on Tuesday. Most of the Hollywood celebrities who have graced the farm with their presence in recent weeks - Martin Sheen, Danny Glover, Laura Dern and others - were safely asleep in their beds. But Daryl Hannah was there, along with a diehard group of protesters who have made tree-sits their speciality.

The police spent eight hours clearing the site and making 40 arrests. They were acting on behalf of the landowner, a certain Ralph Horowitz, who has been fighting for three years to rid the parcel of land of the farmers he regards as squatters and replace the fruit and vegetable patches with a warehouse.

This was a battle that involved everyone, including LA's Mayor, Antonio Villaraigosa, who agreed with the protesters that the urban farm was an important symbol of hope in a frequently hopeless neighbourhood and deserved to be kept intact.

Mr Villaraigosa negotiated with Mr Horowitz up to the last minute to find a financial deal to save the farm. His best offer was a $16m (£9m) buyout, including a $10m grant from a private foundation, which represented a considerable mark-up on the $5m that Mr Horowitz paid for the land three years ago.

"Today's events are disheartening and unnecessary," the Mayor told a news conference. "After years of disagreement over this property, we had all hoped for a better outcome." Mr Horowitz, however, said he was, more than anything, alienated by the vehemence of his opponents and that it wasn't, in the end, about the money. "If the farmers got a donation and said, 'We got $50m, would you sell it to us?' I would say no. Not a... chance," Mr Horowitz told The Los Angeles Times.

The battle over the farm goes back at least 20 years. The city bought the land from Mr Horowitz in the mid-1980s so it could build a rubbish incinerator. That plan, though, drew vehement protests from local residents and was dropped. When the riots broke out in 1992, the city leased the plot to a food bank, which encouraged local people to farm it.

Mr Horowitz then launched a legal campaign to get the land back, and in 2003 he talked the city into selling it to him. The fate of the farmers has flitted in and out of court ever since, with another hearing scheduled for next month. The 350 farmers have, in fact, been slowly moving out as the Hollywood celebrities have moved in, lending the saga an extra surreal tinge. The city has been quietly finding alternative locations for them, including one seven-acre plot a few miles to the south.

That, though, has not been part of the theatrical script. Baez was the first big-name celebrity to climb the walnut tree and sing "We shall not be moved", in both English and Spanish. Her friend Hannah, who had not previously heard of the farm, then became enthused about the cause and moved into the plot on the corner of 41st Street and Long Beach Boulevard for the duration.

There she made common cause with the likes of John Quigley, who sat in a threatened valley oak tree in northern LA county for several weeks in 2002, and Julia "Butterfly" Hill, who spent two years up a redwood tree in northern California in the 1990s. "I'm very confident this is the morally right thing to do, to take a principled stand in solidarity with the farmers," Hannah said moments before her arrest.