To coincide with the launch of a report by the Carbon Disclosure Project analysing the carbon emissions of the UK's biggest companies, a broad coalition, including major companies and over 60 MPs, have demanded that the Government set out a robust framework for the introduction of a mandatory carbon reporting standard.

The signatories of an open letter to the Prime Minister from the Aldersgate Group, a membership organisation convinced of the economic benefits of high environmental standards, are challenging the Government's current position regarding the corporate disclosure of carbon emissions. The Group is highly critical of the decision to weaken a provision in the Climate Change Bill for a clear path to legislation at the earliest practical opportunity. It argues that the Government's new strategy, which includes a review in over three years time, "does not reflect the urgency or magnitude of the issue, nor correspond with your (Gordon Brown's) vision for robust and transparent carbon accounting under the (Climate Change) Bill."

Signatories included Liberal Deomcrat leader Nick Clegg, as well as over 25 Labour MPs, including former Environment Ministers Elliot Morley MP and Michael Meacher MP, and Sir John Harman, former Chairman of the Environment Agency.

The letter states that:

- Despite the existence of widely supported standards and voluntary initiatives such as the Carbon Disclosure Project, the reporting of clear and comparable quantified information on carbon emission from the corporate sector, representing a significant proportion of the UK's emissions, remains inconsistent and variable.

- The signatories believe that a common protocol that is consistent with international financial reporting standards would be a significant driver for change and competitive advantage in the corporate sector.

- A robust framework would give certainty to the business community and attract the significant wealth creation and jobs that London's role as a credible carbon finance capital of the world would deliver.

Aldersgate Group Chairman, Peter Young, who wrote the letter, said:

"The fact that over 50 MPs have signed this letter is testament to the widespread support for mandatory carbon reporting. Business leaders, green campaigners and politicians are uniting around one clear message - it is time that businesses report their carbon emissions in a clear and transparent way."

Former Environment Minister and Aldersgate Group member, Elliot Morley MP, said:

"It is absolutely essential that we know how much CO2 companies are pumping into the atmosphere if we are to have any chance at all of combating the disastrous consequences of climatic change".

Dr. Matthew Kiernan, Chief Executive, Innovest Strategic Value Advisors, said: "With the near-certainty of climate regulation in America looming, the centre of gravity of carbon accounting can be expected to migrate across the Atlantic. Indeed, much progress has already been made in both the U.S. and Canada. In the absence of prompt action and forceful leadership, London could very well see its role as the carbon finance capital of the world become eroded."

Atkins, Co-operative Insurance (CIS), The Co-operative Bank, Tridos, United Utilities, Veolia and Water UK are among the companies and organisations who have signed the letter.