National Party Leader John Key says Helen Clark could change her mind on climate taxes after the election and can't be trusted.

"Just 12 months ago Helen Clark said her goal was for New Zealand to be 'carbon neutral'. She hasn't dropped that goal, and now says she is making changes 'to ensure political support'. 

"That means she has only backed down because she had to.  She has also said the rising petrol price means she can delay the scheme.  What happens if petrol prices stop rising?"

Mr Key says if Labour and the Greens were to form the next Government then all bets would be off.

"Struggling households should prepare for the regional and bio fuels petrol taxes as well.  Labour still wants to push through the regional petrol tax legislation, but Helen Clark wants us to believe it won't be added next year. Yeah right!"

"We have seen these sorts of stunts before.  Labour promised a minor tax cut before the 2005 election then cancelled it afterwards because taxpayers weren't grateful enough.  Now, after arguing against significant personal tax cuts for nearly 10 years, they have magically decided they are a good idea.

"Having cancelled the only personal tax cuts on offer in the past eight years, and having sacrificed borrowers to hire more bureaucrats and buy train sets, Helen Clark now expects struggling households to believe that she won't change her mind again when it comes to the timing of climate change and transport taxes.

"Helen Clark is now so confident her officials have got the figures right that she has changed her mind.  What happens if those figures change again?"

Mr Key says National supports the principle of the Emissions Trading Scheme but has had reservations about the timing of the legislation and the effect on households. 

"We need to take the time to build a consensus on this issue, and ensure that the wider economy is not sacrificed in the pursuit of this scheme.

"The simple reality here is that you can't trust Labour on climate change, and you can't trust them on tax.  The lesson we have learnt is that the Helen Clark you see before an election is a very different Helen Clark to the one you see after an election."