The company said its electricity bills will increase by 8.8%, while gas prices will rise by 10.6% on estimated annual bills from June 1. 

It said an average customer will see a rise of almost €168 for electricity and €170 for gas.

Citing wholesale energy costs driven by instability in global energy markets, the company said it absorbed these increases “for as long as possible”.

“This is our first price increase in three and a half years,” managing director Eric Mullane said. 

“However, wholesale energy costs have continued to rise sharply, and it is simply not possible to hold out indefinitely. We will continue to do everything we can to minimise the impact on our customers and to help them control their energy costs.”

Price comparison site Bonkers.ie said the decision will affect around 180,000 electricity customers and 60,000 gas customers.

Its head of communications Darragh Cassidy said the move was not surprising.

He said several suppliers had raised electricity prices by between 10% and 15% last autumn, while PrepayPower, Yuno Energy and Electric Ireland had maintained a price freeze over the winter months.

"This meant that up until now, these suppliers’ electricity prices were around 20% cheaper than the rest of the market. But this was always unlikely to last indefinitely."

Mr Cassidy said gas prices are highly volatile and have risen by 40–50% since the start of the conflict involving Israel, the US and Iran, and are around three times their level prior to Russian invasion of Ukraine.

He said that, in terms of gas prices, other suppliers are likely to implement similar increases in the coming weeks.

"As a result of this, I’d also expect Electric Ireland, which has close to 1.1 million customers, to announce a similar hike in its electricity prices over the coming days or weeks."