Nova Scotia Premier Darrell Dexter downplayed the expected cost of Muskrat Falls for ratepayers on Thursday saying the subsea cable system designed to bring 500 megawatts of hydroelectricity into the province will drive power rates up by less than one per cent.

Emera Inc., Nova Scotia Power's parent company, has not said what the $1.5-billion project will cost ratepayers, but the premier leaked some details on Thursday.

Company executives have been briefing provincial politicians this week about the documents they plan to file to the UARB.

"What the filling will say is that the impact on rates for Nova Scotians will be less than one per cent for the first five years and then stable and then decline over the balance of the life of the contract with Maritime Link," said Dexter.

That runs counter to what Liberal politicians have suggested. Dexter accused the Opposition party of "fear mongering" and said the slight rate increase is not going to drive up the cost of electricity in Nova Scotia.

The 180-kilometre cable could see as much as 40 per cent of the electricity from the 824-megawatt project in Newfoundland and Labrador moved to Cape Breton. It's the largest investment Emera Inc. has ever made.

Muskrat Falls is expected to produce power by late 2017.