"Enbridge needs to learn about public relations. You don't come in and treat people that way," said Garneau in an interview On the Coast with Stephen Quinn on CBC Radio One in Vancouver.
The former astronaut and current member of parliament for Westmount-Ville-Marie also criticized the Conservative government for being "bulls in a china shop" in its support for the pipeline that would stretch nearly 1,200 kilometres between Bruderheim, Alberta and Kitimat, B.C.
Garneau says there's still scientific work to be done in assessing potential risks associated with the pipeline project, adding that the Conservative government should not look at environmental assessments like the Joint Review Panel as a burden, but as a necessity.
His comments come as five protesters were arrested and charged with trespassing Tuesday for sneaking into and disrupting the federal review panel's Vancouver community hearings into the Northern Gateway Pipeline, which are closed to the public.
Preparing for upcoming debate
Garneau is in Vancouver for the first Liberal leadership debate, which is set for Sunday, Jan. 20 at 1:00 p.m. PT at the Westin Bayshore.
He is running against Justin Trudeau, Martha Hall Findlay and six other candidates in the race to replace Interim Leader Bob Rae.
Earlier in the day, Garneau unveiled his national economic strategy, saying the world's economic focus is shifting to Asia and the Canadian economy will stagnate unless it works harder to improve trade with the region, including China, India, Singapore and Vietnam.
Garneau laid out a four-point plan to increase Asian trade, including clear rules on foreign investment, improving road and rail lines to help the movement of goods, and protecting the environment through science and evidence-based research.
He also said Canada must partner with aboriginal communities on the understanding that the country's economic success is tied to the success of First Nations.
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