TORONTO -- An average 17 per cent reduction in electricity bills this summer in Ontario is coming with a price tag of up to $1.4 billion a year in extra interest costs.

Those extra costs will ultimately come due for ratepayers in the future.

The Liberal government unveiled its plan today to cut hydro bills, which are the biggest political issue it faces less than a year-and-a-half away from an election.

The across-the-board relief, which comes in addition to an eight-per-cent rebate that took effect Jan. 1, is being achieved by refinancing already long-term power generation contracts over even longer terms.

Premier Kathleen Wynne says over time it will cost a bit more and will take longer to pay off, but it is fairer because current ratepayers don't have to shoulder the entire burden of huge system costs.

Several other measures were announced today to give low-income, rural and northern residents additional savings, which will cost the government $2.5 billion over three years.

The delivery charge for on-reserve First Nations residential customers is being removed.

Rural ratepayers covered by some local utilities will se their distribution costs reduced.