A group of Quebecers has asked the courts for permission to proceed with a class-action lawsuit against Hydro Quebec.

The Switched On Coalition/Coalition Peuple Allumé wants a refund of the $1.2 billion it says the utility overcharged customers from 2008 to 2015.

It wants a refund of a bit more than $50 per household for seven years -- $365 -- or a ten percent reduction in the cost of electricity.

More than 30, 000 people have signed up for the lawsuit since April.

Lawyer Bryan Furlong said he will argue that the Energy Board should not have approved the rate increases that were requested.

"Certain numbers when you crunch numbers are inaccurate and we were told that certain people know they are inaccurate. So our lawsuit, class-action, is based on that, it's quite simple, it's based on that. So if you go in front of the Regie and you state something which is inaccurate and the Regie renders a judgment, well I'm asking you, is it a proper judgment?" said Furlong.

Hydro Quebec is a crown corporation all profits are collected by the provincial government and used as general revenue.

A spokesperson said the overcharging was less than one percent of revenue per year, but that there have been many years when electricity was supplied to customers at a lower cost, and that Hydro Quebec has had both surpluses and shortfalls.

When the overcharging allegations were made earlier this year, then-Energy Minister Pierre Arcand said that customers who may have been paid more had already been paid back because the money was used to balance the provincial government's budget.

The current Energy Minister, Pierre Moreau, said he would be very surprised if it could be demonstrated in court that Hydro Quebec overcharged customers, saying that the provincial Energy Board always sets the rates for electricity.

Hydro Quebec's demands for rate increases since 2015 have been refused, with the utility only allowed to increase rates by 0.7 percent, less than the rate of inflation.

In August Hydro Quebec asked for a 1.1 percent rate increase for next year, and the Energy Board will make its ruling in March 2018.