A word of warning has been aimed at power firms, which is just days prior to the increase in bills that have been seen, with Prime Minister John Key cautioning them not to use the contentious Emissions Trading Scheme as an explanation to score in more amount of money from customers.

Power firms are putting up their prices, so as to help cover the expenditure of penalties that they will reimbursing for emitting greenhouse gases under the ETS, which tends to have an effect on them from Thursday.

However, the Government is angry at the justification.

“I do not wish to see gouging as a consequence of the Emissions Trading Scheme”, says Key.

Energy and Resource Minister, Gerry Brownlee has also spoken of his anxiety, saying that the Companies need to keep a close watch that they do not make use of it as an excuse to place its prices upwards.

Mercury Energy is raising its prices by 3.3%, although, it will not be hit too much by the ETS, with the majority of its power already coming from renewable sources.

Contact's prices are increasing by 3.2%, but a few of its Dunedin customers might face increases in the twice the number.