Npower’s decision to introduce a 5% price increase in the New Year has been branded “herd mentality” and “a bitter blow to consumers”.

Npower will set a 5% increase for its domestic gas and electricity customers from January 4.

It marks the company’s first increase in its standard domestic prices for more than two years and comes in the wake of price rises from another three of the UK’s ‘Big Six’ energy suppliers: Scottish Power, British Gas and Scottish & Southern Energy.

EDF has introduced a price freeze until March 1 while EON is holding prices until January 1 but is yet to reveal what will happen then.

Energy watchdog Consumer Focus has branded the rise as “more bad news for consumers”.Audrey Gallacher, head of energy, said:”npower customers will have been bracing themselves for this bad news after the increases from other firms, but that won’t make them any less worried about affording their bills this winter.

Gallacher added that “with four of the Big Six suppliers having now announced price rises averaging 6%, the focus on Ofgem’s review of whether energy prices are justified will be even sharper”.

Ann Robinson, director of consumer policy at uSwitch.com, said: “This is the tipping point, with four of the six major energy suppliers having now chosen to hike their prices this winter.

“The majority of households will now be hit hard at a time of year when many struggle to meet their bills anyway.

“The herd mentality has kicked in and the need for affordable energy through the cold winter months has been trampled underfoot in the stampede to raise prices. This is a bitter blow to consumers.”