CALGARY -- The federal government's lengthy balancing act between the energy industry and the environment will soon be tested as it rules on the fate of two major oilsands pipeline projects.

The government has committed to decide by Friday on two projects proposed by Enbridge: the Line 3 pipeline replacement and Northern Gateway pipeline.

Reuters reported Thursday that the government would announce its decisions on Tuesday, citing sources it said were familiar with the matter. The government declined to comment on the report, saying only that the decision will be announced after the decision is made.

Line 3 would replace a decades-old conduit that runs from Hardisty, Alta., to Superior, Wisc., and double its capacity. Enbridge has described it is an essential safety and maintenance project.

In the politically charged debate over pipelines, Line 3 has been largely overshadowed by other projects such as the Trans Mountain expansion and Energy East.

The National Energy Board recommended Line 3's approval in April, subject to 89 conditions. There are some expectations, at least within industry, that Ottawa will sanction it. Such a decision would be the first oilsands pipeline expansion on Prime Minister Justin Trudeau's watch.

Trevor McLeod, director of the Centre for Natural Resources Policy at the Canada West Foundation, said the government has been trying to achieve the delicate task of building acceptance of pipelines with stringent environmental regulations, such as a carbon tax.

"He's decided on what I call the thread the needle strategy -- he's decided we don't have to choose between economic development and energy development and the environment," said McLeod.

Approval of the $7.5-billion Line 3 project would allow for exports to increase from 390,000 to 760,000 barrels a day since Enbridge has been running the 1960s-era pipeline at reduced capacity. It also has the potential to be expanded to 915,000 barrels a day with further permitting and pump stations.

While the energy industry would welcome Line 3, environmentalists have decried the project for the increased emissions it would allow.

The government also has to decide on whether to proceed with further First Nations consultations on Northern Gateway after a Federal Court of Appeal ruled earlier this year that the previous Conservative government had failed in its duty to consult. Trudeau has signalled in the past that he's against the project.

Mike Hudema, climate and energy campaigner at Greenpeace Canada, said if Line 3 were approved but Northern Gateway rejected, it would set back Canada's efforts to combat climate change.

"It will be a great day of celebrations for communities in northern B.C., but a bad day for climate action in Canada overall," said Hudema. "You're opening up new resources and emissions."

Line 3 has seen significant opposition in Minnesota, where those opposed have launched legal battles and challenging, and Hudema said that opposition will likely grow if it's approved in Canada.

Grand Chief Derek Nepinak of the Assembly of Manitoba Chiefs agreed.

"The climate-killing Enbridge Line 3 tarsands pipeline will never see the light of day," Nepinak said in a statement.

"As a result of the co-ordinated opposition by Indigenous People in both Canada and the U.S., exerting their own sovereign jurisdiction and supported by their non-Indigenous allies, Line 3 will end up on the same scrap heap as Enbridge's Northern Gateway tarsands pipeline. Line 3 needs to be repaired and then shut down and cleaned up."

The government has committed to factoring in the emissions findings and feedback from enhanced consultations and the NEB's recommendations, but a spokesman for Natural Resources Minister Jim Carr emphasized they will also factor in economic benefits.

"We have been clear that environmental protection and economic development must go hand-in-hand," said Alexandre Deslongchamps in an email.