Citing an unnamed source, CBC News has reported that the Trudeau government has worked out an arrangement that could enable completion of the Trans Mountain Pipeline Expansion project.

This agreement in principle has been reached between Finance Minister Bill Morneau and the pipeline's major shareholder, Kinder Morgan.

Details are reportedly still being finalized before an agreement can be released.

The $7.4-billion project would triple shipments of diluted bitumen to 890,000 barrels per day. It would flow from Alberta through Trans Mountain's system to Burnaby.

If the pipeline project is completed, it would result in a nearly seven-fold increase in oil-tanker traffic in the waters off Vancouver.

In the meantime, First Nations are challenging the National Energy Board's approval in the Federal Court of Appeal.

"Canada cannot indemify against the risks of not respecting Indigenous title and rights," Union of B.C. Indian Chiefs president Grand Chief Stewart Phillip said in a news release on May 16.

Texas-based Kinder Morgan spun off its Canadian operation into a separate publicly traded company called Kinder Morgan Canada.

The parent company owns 70 percent of the shares.

Prime Minister Justin Trudeau has declared that the pipeline will be built.

In any attempt to bring this about, the federal government has several options, including:

* buying Kinder Morgan's stake in Kinder Morgan Canada and then selling the project after it's completed;

* providing financial guarantees to Kinder Morgan Canada should the pipeline not be completed in time to meet its contractual obligations to shippers;

* providing financial guarantees to investors who are interested in buying Kinder Morgan's stake in Kinder Morgan Canada.

In early April, the parent company announced that it was suspending all nonessential spending on the Trans Mountain project.

At that time, it has given a deadline of May 31 to achieve certainty before it would resume investing in the pipeline expansion.

Critics in the environmental movement have often suggested that the Trans Mountain project is not financially viable.

The Canadian Taxpayers Federation has insisted that nationalizing the pipeline is a "terrible idea".

And business journalist Paul McKay has accused the media of "malpractice" in its failure to report on what he calls the "bitumen bubble".

"In a recent three-part series of investigative reports published by The Energy Mix, I laid out an evidence-based argument that there is no credible business case to support an expansion of oil sand exports or the proposed Trans Mountain and Keystone XL pipelines," McKay recently wrote on the National Observer website.