The PN has filed a parliamentary motion to amend two legal notices published last month that will see consumers receive revised utility bills to make up for overcharging due to an “anomaly” in the law.

According to these legal notices, the "adjustment" will only date to January of this year.

The PN is proposing that compensation should be backdated to January 2014, when the current bimonthly billing system had been introduced. 

Last month Energy Minister Miriam Dalli said that on average, 80% of families will receive an adjustment of between €0 to €8, with the figure varying depending on their consumption patterns.

Just three months before, a court had ruled that ARMS, the company that bills consumers for water and electricity, breached the law when it issued bills for Darren Cordina and Melvin Polidano on a pro-rata basis rather than on an annual cumulative consumption basis.

For years, ARMS has been issuing bi-monthly bills using a staggered calculation system. The first 2,000 units of electricity are charged at one rate and further consumption at higher rates.

For every kWh of the first 2,000kWh consumed in a year, residents should be charged 10.47c and then pay 12.98c for every kWh for the next 4,000kWh, 16.07c per unit on the next 4,000kWh and so on.

However, ARMS splits up this allocation pro rata according to the number of bills a consumer receives in the same year. This means that if a residence is billed every two months, the first 2,000 units are split between six bills, amounting to an allocation of 333 units per bill at 10.47c per unit.

If a residence consumes fewer than 333 units in a two-month billing period, the remaining units at the cheaper rate are not brought forward to the subsequent bills. The allocation is therefore lost.

Last year, a report by the National Audit Office found that consumers could have paid “extra charges” totalling €6.5 million on their electricity and water bills.  

On Friday the PN said it was tabling the motion to ensure that consumers are refunded all the money that was stolen from them through the current billing system.

The PN motion was presented by MPs Mark Anthony Sammut, Ryan Callus, David Agius and Karol Aquilina.