Critics of New Zealand's Emissions Trading Scheme are getting their chance to say what they believe is wrong with it.
A review of the scheme was promised for this year, and the review chairman David Caygill has called for submissions on what changes, if any, should be introduced.
One of the main issues will be a possible extension of measures making it easier for big greenhouse gas emitting companies to adapt to the cost of mitigation.
The measures effectively halve the cost companies face for their emissions, and it was suggested they might be extended when the terms of reference for the review were unveiled just before Christmas.
Some companies are expected to push for an extension beyond the original expiry date of December next year.
The review is required to present its draft report to the Government by June.