CALGARY - The National Energy Board says it has officially started the clock on its review of the contentious Energy East pipeline project.

The NEB now has 21 months to hold hearings along the 4,500-kilometre route from Alberta to New Brunswick and report to government whether the pipeline is in the national interest.

While the review is only now beginning, the debate around the project has already become polarized, with environmental groups and some First Nations and politicians expressing total opposition. Meanwhile, the oil industry, along with the premiers of Alberta, Saskatchewan and New Brunswick, have come out staunchly in favour.

The energy board says this will be one of its most innovative and extensive project reviews ever and one in which all Canadians will have an opportunity to weigh in.

The review will factor in greenhouse gas emissions caused by the construction of the project, but potential upstream emissions will be left to Environment and Climate Change Canada to tally and for the federal cabinet to factor into its final decision.

The Energy East pipeline would open new markets for Canadian oil by carrying 1.1 million barrels of Alberta and Saskatchewan crude to refineries in Eastern Canada and an export terminal in New Brunswick.