Thousands of companies worldwide will be pushed to report on their environmental strategies and performance under proposals to be finalised at a UN summit in Rio de Janeiro this week.
The move is being resisted by some countries, including the US, Canada and India, according to people close to the summit negotiations, because of fears it will add to companies' regulatory burdens.
But it is being backed by many European countries, including the UK, which has included a leading campaigner for the measure, British insurer Aviva, in its official delegation.
A final decision will be made at the end of this week by more than 100 world leaders at the Rio+20 UN conference on sustainable development, which the UN says is the biggest event it has held.
Named because it comes 20 years after the 1992 UN earth summit in the same Brazilian city, Rio+20 has been targeted by a group of businesses and investors that say both companies and investors benefit from doing long-term forecasts for shortages of energy, water and other resources.
Their campaign has led to the inclusion of a section in the summit text that leaders are to agree by this Friday that says governments should develop a "model for best practice and facilitate action" for so-called corporate sustainability reporting.
One of the models cited by campaigners as an example is Denmark's "report or explain" requirement for large companies to either report on their behaviour or explain why not.
About 95 per cent of the 250 largest global companies now report on their corporate responsibility activities, a jump of more than 14 per cent from 2008, according to a KPMG survey. But two-thirds of those that do not report are based in the US, the world's biggest economy, and the picture is more mixed among smaller businesses.
Separately, the UN is backing a measure for stock exchanges to push listing companies to do more reporting on their sustainability strategies. This is not included in the Rio+20 text leaders will negotiate, but backers hope some exchanges might announce steps to encourage such reporting this week in Rio.