The Parliamentary Commissioner for the Environment says any new version of an Emissions Trading Scheme will have its problems.
The scheme is being reviewed following the change of Government in November.
Appearing before a parliamentary select committee, the Commissioner, Jan Wright, said, despite the imperfections of the original scheme, it is the right framework.
Dr Wright says her office has a staff member attending select committee hearings on changes to the scheme.
But she is not expecting a new version of the emissions trading scheme to be perfect, as she says it is such a complex issue.