Companies that are publicly listed in Britain will have to make annual declarations of their carbon emissions once the Climate Change Bill at present going through Parliament becomes law.

The Government adopted an amendment on Monday making such annual reporting mandatory following a campaign spearheaded by international development agency Christian Aid.

Two weeks ago the organisation launched a major advertising campaign asking the public to write to Parliament and the Prime Minister on the subject.

Paul Brannen, Christian Aid's head of campaigns, said that the move was great news and showed that the Government was finally taking action that was "long overdue".

"It would have been impossible to believe the Government is taking climate change seriously if it had left declaring emissions up to the whim of company directors," he said. "That is the situation at present and it has led to variable, unquantified and non comparable information in this area.

"UK businesses fund up to 15 per cent of carbon emissions around the world. With greater transparency we'll have much greater clarity on where the corporate responsibility lies to cut those carbon emissions."