The Labour Party says Prime Minister John Key's late decision to go to the Copenhagen summit on climate change shows he's been getting bad advice.
Mr Key changed his mind about attending the leaders' meeting at the summit after, he says, he got new advice from New Zealand's negotiating team that he should go.
But Labour Party climate change spokesperson Charles Chauvel believes the change of heart has more to do with advice from other leaders than with advice from his own team.
In Mr Chauvel's view, the Prime Minister "got some independent advice at the Commonwealth Heads of Government Meeting from people like Gordon Brown and Kevin Rudd, and realised that if he didn't attend it wouldn't look as if he really took the issue of climate change seriously."
Mr Chauvel says Mr Key has been poorly advised about a range of issues, including the rejigging of the Emissions Trading Scheme to align with Australia's.
Hard work lies ahead - Greenpeace
Meanwhile the Green Party and Greenpeace say Mr Key will come under pressure at Copenhagen over New Zealand's emissions reduction target of between 10% and 20%, when other countries have much bolder plans.
Greenpeace climate campaigner Simon Boxer says the science demands that emissions be reduced by 40% by 2020 and New Zealand's target isn't good enough.
Mr Key's decision to go to Copenhagen is the right one, Mr Boxer says, but the hard work lies ahead. The Prime Minister needs to show, he says, that New Zealand is taking the issue seriously and is prepared to reduce emissions.
Political momentum growing, says PM
Mr Key had previously said he had no plans to attend the conference, but on Thursday he announced he'd reassessed his position.
Although a binding agreement is still unlikely, he says, political momentum is growing. New Zealand will have credibility at the conference with its emissions reduction target, he says.
Former Prime Minister and World Trade Organisation chief Mike Moore says Mr Key could cement international relationships and make New Zealand's climate change case at the conference.
'Very significant' so many leaders attending
The Green Party's spokesperson on climate change, Jeanette Fitzsimons, says it's very significant that so many world leaders are attending. "They send somebody more junior if they just want to say no and obfuscate," she says.
Almost 100 world leaders - including US President Barack Obama - have now indicated they will attend.
The conference, which aims to formulate a successor to the Kyoto Protocol, runs for two weeks from 7 December.