Npower has become the first supplier to raise prices on its standard energy plans and the industry expects other major energy suppliers to follow suit.

According to price comparison site SimplySwitch.com, npower’s price increases of 17.2% for gas and 12.7% for electricity, will add approximately £159 to the average gas and electricity bill. The increase will be implemented from tomorrow. Because this move follows a steady rise in wholesale energy prices, other major suppliers are expected to raise their price plans accordingly.

The announcement comes after mounting speculation concerning price rises in utilities. Following npower and British Gas’s recent announcements that they were hiking their prices on market tracker products, in addition to a further increase to npower’s online plan, experts at uSwitch last week predicted a 15% rise in utilities from another of the UK’s main suppliers.

Karen Darby, founder of SimplySwitch, said: “Historically, when one of the big suppliers increases prices, the others are quick to follow. Analysts were predicting gas price rises of around 15%. However, if the other suppliers follow npower’s lead and raise prices by over 17%, householders will really feel the pinch.”