Members of the West Australian Government’s opposition party have accused the state’s Premier of going back on a pledge on water charges.

Premier Colin Barnett reportedly told some voters in the lead up to the most recent election that the worst was over as far as utility price rises go. Now the new WA state budget has shown water prices are set to jump by 21 per cent over the next three years, according to the opposition.

Opposing MP Dave Kelly claims average bills in 2016 will be almost double those in 2008, also saying “two monthly billing was really just a way to disguise the increases that they planned for people's water bills...when they [the WA Government] moved to two monthly billing we suspected that one of the reasons they did it is so people wouldn't notice the massive increases that they had experienced and were going to be experiencing in their water charges.”

The Western Australian Water Minister has rubbished the claims, saying there is no price-rise of the amount Mr Kelly claims currently being planned, and that increases will be modest at worst.

“Look, the forward estimates are simply predictions for Treasury purposes,” Water Minister Terry Redman said, “every year, the State Government makes a decision around the pricing for water... if you looked at last year's figures in the forward estimates it predicted a nine per cent increase, we've gone for a six per cent increase.”