To the casual observer, it would appear that the former World Wildlife Fund has moved light years from its cuddly 'save the panda' image, and reinvented itself as the UK's biggest corporate responsibility consultancy.
But Robert Napier, the charismatic chief executive of its UK arm, bristles at this. "We are not consultants," he insists in his clipped, Cambridge University brogue. "Our job is leverage, and a bit of carrot and stick."
WWF's ultimate aim, he explains, is to move the world to a position where mankind and nature live in harmony. To achieve this, humans must reduce their consumption of the earth's resources so they are using only one planet's worth to survive, rather than the 1.3 currently consumed. Most restraint needs to occur in the west - western Europeans currently devour the resources of three earths, and north Americans five.
"My heart lies on an unspoilt hillside," Napier confesses. "What right have we as a generation to mess it up?"
Although WWF doesn't focus its attentions on the private sector to the exclusion of governments and individuals, it does regard corporate behaviour as crucial if there is to be any prospect of stopping the destruction of the natural world.
"It's very simple - for a sustainable planet, we require sustainable companies," says Napier. "But one of the difficulties is that the problems companies will face are not typically within a company's current planning horizon of three to four years - they'll say 'climate change won't affect us in the next price round, so why bother?'
"Our role is to help firms understand that the impact of issues such as climate change will not be linear. But this creates opportunities as well as risks, so we try to help companies take positive action."
But it's "not all cosy stuff", he points out. If a company refuses to engage with an issue, WWF is not afraid to challenge it publicly - it took out newspaper ads in 2003 attacking BP's oil pipeline in the Caucasus, and gave back a donation from Lafarge after the aggregates company refused to give up plans to build a superquarry on the Scottish island of Harris.
Ironically, before he joined WWF six years ago, Napier was chief executive of Redland, the company that first applied for permission to open a quarry on the island.
Napier is acutely aware of the risk of greenwash, and ensures there is a clear distinction between talking to or working with a company and taking cash from it. WWF's five-year partnership with HSBC involves a donation of £12m, but this was only agreed after 18 long months of "sizing each other up", says Napier. "We have a rigorous internal assessment process that governs who we will take money from and who can use the panda." About 10 per cent of WWF's revenue comes from corporate sources.
Although WWF is "winning battles", Napier is frustrated that it is not "winning the war". He suggests he might now look to turn the success WWF has enjoyed with the private sector to governments and individuals.
"We have to up our game," he admits. "We must improve the solutions that consumers can take, and go for a bigger push on big issues to get governments to take more action."