Oil giant Shell is being held to account by ethical investors, as shareholders take advantage of the Companies Act 2006.
A resolution, which calls on Shell to prove that controversial oil sands in Canada are sustainable, will be voted on at the company's AGM in May.
A coalition of individual and institutional investors campaigned through 2009 amid growing concerns about the financial, environmental and social implications of these projects.
The sands are the second largest oil resource in the world and in converting the oil to fuel, produce on average three times the greenhouse gases of conventional extraction.
Catherine Howarth, chief executive of FairPensions, the organisation that coordinated the initiative, says: "This resolution brings together the full spectrum of investors from major fund managers to small shareholders.
"All are united in registering concern with the risks involved in Canadian oil sands, and this reflects rising public concern not just with oil sands but with companies' impact on climate change."
Canada is already on course to miss its Kyoto protocol targets and the expansion of oil sands will make it virtually impossible to cut its emissions from 1990 levels.
The resolution raises concerns for the "long-term success of the company" and takes into account expected carbon price rises, oil price volatility, regulation of greenhouse gas emissions and the legal and reputational risks arising from environmental damage.
Mark Mansley, investment director at Rathbone Greenbank, says this could lead to more corporate accountability: "We would be very comfortable if we end up seeing a number of shareholder resolutions each year at leading companies."
Mansley supports engagement as an option for ethical investors and believes it has been given a boost by provisions within the Companies Act 2006.
"One of these was 'enfranchising indirect investors' to enable those whose shareholders are held through a nominee to essentially enjoy all the rights of direct shareholders," he explains.
A key benefit of this is the ability to propose resolutions, or to work with clients to drum up support for a resolution, a role Rathbone Greenbank fulfilled in the case of the oil sands.
Greenpeace UK is unsurprisingly also critical of Shell's actions, and executive director John Sauven believes its reputation will be severely tarnished.
"The exploitation of the oil sands is an environmental scandal on a massive scale, and is set to become a campaign battleground for years to come," he says.
"Shell's shareholders should know that once the public finds out what's really going on in Canada the company's reputation will suffer badly, and no amount of expensive advertising will help."