Business leaders from many of the world's largest companies yesterday called on politicians to agree a successor to the Kyoto Accord at UN-backed talks in Copenhagen later this year, arguing that a global deal to address climate change would "remove uncertainty, unleash additional investment, and bolster current efforts to revive growth in a sustainable way".

The call featured in a new six-point manifesto, dubbed the " Copenhagen Call", released at the close of the World Business Summit on Climate Change in Copenhagen.

It offers one of the most unequivocal declarations of support for a meaningful climate change deal delivered to date, calling for "ambitious" emission-reduction targets for 2020 and a goal of reducing global emissions by at least half by 2050.

It also calls for a new global framework for measuring and reporting carbon emissions, increased incentives and financial support for clean technologies and climate change adaptation measures, and a new system for funding forestry protection.

The manifesto was presented as a summation of the views expressed at the conference, which was attended by several hundred global political and business leaders, including senior executives from BP, Vattenfall, Duke Energy, BT, Merill Lynch, Saatchi & Saatchi, PepsiCo, and Unilever.

However, critically the organisers of the conference included a disclaimer in the manifesto, advising that it does "not necessarily reflect the views of all participants".

Some green groups criticised the meeting for allowing carbon-intensive firms such as Shell and Duke Energy to attend, accusing them of "hijacking" the debate and promoting relatively high-risk approaches to curbing carbon emissions, such as carbon capture and storage, which would allow the continued expansion of fossil fuel industries.

But Tim Flannery, chairman of the Copenhagen Climate Council which organised the manifesto, downplayed the criticisms, insisting that the nature of the debate at the meeting proved many businesses were fully committed to deep cuts in emissions. "The ambition of the Copenhagen Call shows that business need not be a conservative voice on climate change," he said. " Many of the businesses represented at this significant event in the lead up to COP15 want brave decisions that will tackle this most wicked of problems."

Speaking to BusinessGreen.com, Steve Howard, chief executive of The Climate Group, agreed that the manifesto was an accurate reflection of the views of those 700 global companies in attendance at the conference. "There was absolute clarity that [a global deal at Copenhagen] is what they want," he said. "There was almost a sense of frustration that things are not moving fast enough... they are already acting and saying that "for us to go all in we need a global deal".

He added that the vocal support of business leaders would significantly increase the liklihood of a meaningful deal being agreed in Copenhagen. " Political leaders are often surprised at the level of support from the business community," he said. "But events like the one this week show every government that there are many in the business community that are progressively onside [with the UN backed talks]."

The release of the manifesto comes just days after UN secretary general Ban Ki-Moon and former US vice president Al Gore opened the summit with a plea to business leaders to step up their support for a global deal.

"We have to do it this year. Not next year – this year," Gore warned. "The clock is ticking, because Mother Nature does not do bailouts."