Why it's set to be a long, hot summer for the climate campaigners

Jane Thynne asks whether the press will once again go on the warpath against green activists

As climate-change protesters begin to plan for another summer of high-profile demonstrations, the biggest challenge to their success may come not from the police or corporate bodies, but from the media.

Activists preparing to step up their protests against airport expansion this year claim efforts at peaceful "direct action" could be undermined by "sensationalism and scaremongering" in the media.

Dramatic claims dominated coverage of last summer's Camp For Climate Action, which was set up on a field outside Heathrow airport. The camp's organisers are now embroiled in a bitter row with the London Evening Standard over front-page claims that its supporters plotted to plant suspect packages around the airport and create security breaches.

The Press Complaints Commission is expected to rule next month on the article, which the organisers claim was a "political hit job" that in effect derailed their peaceful protest and refocused newspaper and television attention away from the fossil fuel debate. They are asking the PCC to rule that the article was fabricated and based on inaccurate evidence.

The Evening Standard describes the story as "a fine piece of old-fashioned journalism", The issue of a threat to Heath- row at the height of the holiday season was a major news event. According to Doug Wills, managing editor of the paper: "We robustly defend our coverage. It was a subject of widespread national interest."

The week-long camp, which attracted an estimated 2,000 protesters, promised "a day of mass direct action aiming to disrupt the activities of the airport and the aviation industry – though in the interests of public safety, there will be no attempt to blockade runways."

Its website announced: "The direct action from the camp will be inspired and creative; it will be at many different locations and take many forms. There will be small groups taking autonomous actions and well-advertised mass actions. It is the policy of the Camp for Climate Action that everyone is welcome to come to the camp on the condition that they do not cross the perimeter fence at Heathrow into places where planes are (ie, runways, taxiways, storage areas and air traffic control) for the entire duration of the camp. This is to avoid putting the general public and airport staff in danger, and for the safety and security of the camp as a whole."

Yet on 13 August, as an eco-village of tents and flatpacks emerged in a scrubby field north of Heathrow, the Evening Standard ran a front-page story headlined: "Militants in plot to paralyse Heathrow".

The article, with Robert Mendick's byline, was based on the account of the Standard's staff reporter, Rashid Razaq, working undercover at the camp. He said he had overheard remarks from a group calling themselves "The Elders" urging protesters to leave bags around the airport and climb the security fence. The report said: "Some plan to pose as customers to get into McDonald's and Starbucks in the terminals and then cause trouble."

Mr Razaq reported that "late that night I saw two protesters carry out reconnaissance on the security fences".

Elsewhere in the article, this idea appeared as, "two-man teams used the cover of darkness to look for security weak points along the perimeter fence".

The effect of the story was dramatic. It was repeated across the media – including in the Daily Mail, the Telegraph and on Newsnight – and the story of the camp, with its aim of peaceful protest against climate change, was diverted into coverage of the allegations of a plot by protesters. Police and security measures were stepped up.

George Monbiot, the environmentalist who was present at the camp, wrote at the time that: "Shameless exaggerations of the climate protesters' dastardly plans have left us baffled." He said he had never seen nor heard anything of the alleged plot, and did not himself believe it had taken place.

Last week he added: "When I went on Newsnight, we couldn't discuss anything else. It was incredibly frustrating. Every time I tried to talk about climate change, we ended up talking about whether we ourselves were terrorists."

The camp organisers subsequently embarked on a months-long attempt to disprove the Standard's claims. In response to the newspaper's assertion that "two-man teams" had reconnoitred the security fences, they pointed out that "the fences were at least a kilometre away from the camp and not within direct line of sight".

The organisers said the Standard later claimed that Mr Razaq had made a late-night trip to the nearby petrol station for a snack and on the route back to the camp had stumbled across two men tampering with the fence.

They argued this was "completely impossible" because there was only one petrol station in the area, and it would have been impossible to see the fence from the road to that station – a difficulty compounded by the fact it was night time.

The camp organisers sought to rebut claims of a "plot" by "The Elders" to place suspect packages around the airport, and to "cause trouble" in McDonald's and Starbucks.

They said they could produce numerous people to swear affidavits that such comments were not made, and that no group called "The Elders" existed.

And even if the journalist did overhear such remarks, they added, it still did not justify a newspaper splash. "In any large group of people, all kinds of suggestions might get made. If a mere suggestion becomes the standard by which a newspaper can proclaim a secret plot on page one, then virtually anything can get written," one of the organisers said.

Yet the sheer difficulty of disproving that unattributed comments were made by anonymous people at a camp of more than a thousand demonstrators goes to the heart of the problem faced by the protesters in their media battle.

Supporters of Camp for Climate Action accept that their organisation, being leaderless and without hierarchy, is vulnerable to suggestions that are difficult to refute. They organised a daily "media tour" of last year's camp, but were aware that journalists would attempt to report undercover. Many now believe they need a more sophisticated response mechanism than time-consuming retrospective battles with the press through the PCC.

"People who stand up to powerful organisations and interests will always be demonised," says Monbiot. "The only way to counter it is rapid response, but if people want to make accusations, they will, and it is in the nature of what we're doing that this will happen. Because we're a collective, not a corporation, they can say what they like without fear of libel."

Another summer of protest is now being planned, although instead of static camps, a "convoy" of protest – travelling throughout the country by bicycle, horseback or on foot – is envisaged. As well as Heathrow, potential targets for the action, between 23 July and 5 August, include the Kingsnorth power station in Kent where the German power giant E.ON is planning to build the first coal-fired power station in the UK for more than 20 years, and the £40m refining plant run by Greenergy, the UK's biggest biofuels producer, at Immingham on the Humber estuary.

Heathrow is a particular concern to climate change protesters, with consultation on the third runway ending this month and a decision expected from the Government this summer, potentially increasing flights from 480,000 to 700,000 a year.

The saga with the Evening Standard has made Camp for Climate Action organisers think more carefully about how to take control of their own story. Those planning "direct action" this summer are considering a conference to discuss the limits of acceptable protest, and to clarify their aims to press and television before the demonstrations take place.

Alongside the fight on climate change, the battle over the media agenda is one which they have yet to win.