ST. JOHN'S, N.L. -- Critics of Newfoundland and Labrador's Muskrat Falls hydroelectric project are questioning the timing of its approval.

The province's Liberal leader says Premier Kathy Dunderdale's official sanction of the project last night during a ceremony at the legislature in St. John's is premature.

Dwight Ball says there are still several loose ends, including a Federal Court challenge over the assessment that was done on its environmental impact.

N-D-P Leader Lorraine Michael is calling last night's ceremony a sales job aimed at persuading people the project is good for the province.

Private utility Emera simultaneously approved its part of the project, a subsea cable to bring electricity from Newfoundland to Nova Scotia.

Dunderdale says the $7.7-billion megaproject shows her province is becoming Canada's energy warehouse.

Crown corporation Nalcor Energy plans to build the dam and power station in Labrador, which is expected to produce power by 2017.

Critics of the project also say it could burden future generations if it soars over budget.