The arbitrary manner by which Arms Ltd was altering billing periods means certain families are being charged the highest tariffs in peak months, with their quota of cheaper rates left unutilised in other months, Partit Demokratiku said on Saturday.

The party said it had received numerous complaints about this matter and welcomed calls for an investigation.

PD noted that, according to Eurostat, the average residential tariffs did not decrease by 25 per cent as Enemalta had previously projected, but only by 15.6 per cent.

Eurostart figures also indicated Malta the highest average cost of electricity for households in Europe. This suggested that the current tariffs were providing Enemalta with greater revenues and greater return than allowed by the regulator and ran contrary to the tariffs approved by the Malta Resources Authority in 2014.

These had stated that the tariffs were to be applied on a cumulative consumption per annum basis.

PD said Enemalta had also been quoted stating that the Enemalta Act allowed it to bill at a pro-rata basis.

But it was one thing to use this clause to ensure bills were issued in a timely manner, and another when it was used to impose billing periods which pushed consumers into higher tariff rates than allowed when reconciling bills on a cumulative consumption per annum basis, as dictated by law.

PD slammed the Malta Competition and Consumer Affairs Authority, saying the consumer rights regulator's silence was "deafening." And while the function of the regulator for energy and water services was to promote the interests of consumers and other users in Malta, particularly vulnerable ones, PD said it was evident that this role was not being fulfilled.

The role of strong and independent regulators was crucial for protecting consumers from abusive monopolies, PD said.

It emphasised the urgent need of independence as both operator and regulator fell under the same ministry, an anomaly introduced in 2013 by Konrad Mizzi, who at the time served as Energy Minister.

“So far it is very noticeable that regulators are protecting a hidden agenda and consumer rights are in jeopardy,” PD said.