Environment groups and charities working on poverty issues believe the agreement is far too weak.
"We have reached the best possible equilibrium at this point; I think we have a very good outcome," said Brazilian Foreign Minister Antonio Patriota to the BBC.
Denmark leads the EU and both are unhappy with "the level of ambition" in the text. BUt the Danish environmental minister believes it will be signed off anyway.
"The EU would have liked to see a much more concrete and ambitious outcome, so in that respect I'm not happy with it," she said.
"However we managed to get the green economy on the agenda, and so I think we have a strong foundation for this vision that can drive civil society and the private sector to work in the same direction, to understand that environment and the social side must be integrated into the heart of the economy."
The lad negotiatior for the USA called the draft "a good step forward" and admitted it would not be re-opened for discussions.
More than 100 world leaders are expected in Rio from Wednesday to attend the summit.