While the Senate's transport committee recommended the upper house defeat the bill outright, a coalition of Independent and Liberal senators has cobbled together enough votes to rescue legislation to implement the government's planned ban on oil tankers along B.C.'s northern coast.

The outcome was far from certain after the committee that studied the legislation recommended against passing the Liberal plan. The committee issued a scathing report this week saying that, if passed, the bill would stoke a nascent separatist movement in Western Canada, and accused the government of unfairly targeting Alberta's oilpatch at a time of constrained pipeline capacity and cratering oil prices.

The strongly worded report — penned by the committee's chair, Conservative Saskatchewan Sen. David Tkachuk — prompted a backlash of sorts Wednesday night from other senators who called it overly partisan.

Senators rejected the committee's report by a vote of 38 to 53, with one abstention. Now, senators are expected to make amendments at the third reading phase of the legislative process before sending the bill back to the Commons for approval.

The Senate also voted this evening on Bill C-69, the government's controversial overhaul of the environmental assessment process. The Senate's energy committee passed more than 180 amendments to that bill that would, among other things, limit the environment minister's ability to interfere in the regulatory process and stop and start project timelines.

Having passed the Senate, C-69 now returns to the House of Commons with all 180 amendments.

This committee did not function properly and did not function in a collegial matter. I therefore consider it to be a dysfunctional committee. - Sen. Murray Sinclair speaking about Tkachuk's transport committee

While not explicitly written into the Liberal government's 2015 platform, then-third party leader Justin Trudeau vowed to institute a moratorium on oil tankers docking at ports along the northern B.C. coast when unveiling his plan for the environment at a Vancouver-area event in June, 2015.

In describing the legislation, Tkachuk said it is "not as advertised" — that it is not a "moratorium" at all because there is no set timeline, and should be described as a ban. (The Conservative Party recently launched a series of ads with the tagline, "Justin Trudeau, not as advertised.")

In the report, Tkachuk said the legislation was motivated not by a desire to protect the pristine Great Bear rainforest but rather by electoral considerations. He said Trudeau is willing to undermine the Prairie economy to court votes elsewhere.

Tkachuk said Trudeau is "targeting one region, where the political rewards for the government of the day are few, in order to please voters in other regions of Canada — regions where the government of the day has far greater potential to win seats.

"Your committee notes the ruling political party has historically been unable to win a significant number of seats in the region targeted by this bill, and that all credible polls indicate the ruling party will be unable to win a significant number of seats in the upcoming federal election."

Independent Quebec Sen. Andre Pratte said that, while he opposed parts of the tanker ban bill and will offer amendments at the third reading stage, he thought Tkachuk's report did a disservice to the committee's deliberations on the legislation.

While many reports are produced with a degree of consensus — with contributions from members of the committee from different parties — the committee's deputy chair, Independent Quebec Sen. Julie Miville-Dechêne, said there was no such offer from Tkachuk.

Conservative Senator David Tkachuk: 'This was not a waste of time. This was the Senate at its best.' (Fred Chartrand/Canadian Press)

"He said no to any steering committee, as usual. We were therefore unable to decide in a collegial manner how to go about writing the report. My only priority then became to ensure that whatever report was prepared would be put before the Senate promptly so that we can all vote on it," the senator told her colleagues.

"I therefore urge you to emphatically reject this 21-page report, which does a disservice to the Senate and does not do justice to the diversity of opinion among the 139 witnesses who appeared before us."

However, while she was critical of the Tkachuk report, Miville-Dechêne and other dissenting senators did not draft a minority report to respond to the Tory-penned document.

Independent Manitoba Sen. Murray Sinclair said the transport committee is clearly "dysfunctional," given how much bickering there was between members at its meetings and in the chamber Wednesday.

"It's appearing to me, from being here, that this committee did not function properly and did not function in a collegial matter. I therefore consider it to be a dysfunctional committee," the former judge said.

"The committee did not appear to be able to get along very well in its work and deliberations, and that causes me concern because now we are being asked to be parties to this report as members of the chamber."

Sen. Murray Sinclair: The transport committee is 'dysfunctional.' (CBC)

The "dysfunction" label prompted claims of unparliamentary language from the Conservative opposition, with one senator saying the description "defamed" the work of the committee.

Independent Quebec Sen. Rosa Galvez said the mood at the transport committee, of which she is a member, was "extremely unpleasant" under Tkachuk's leadership.

She said the committee's travel, to locations in B.C., Alberta, and Saskatchewan, was essentially a waste of time because dissenting voices were all but excluded from Tkachuk's final report.

"A cost-benefit analysis of this report would be absolutely scandalous," Galvez said.

"Overall, I got the feeling that our work was being undermined and even sabotaged. Rather than conducting an in-depth analysis of Bill C-48, of its weaknesses and limitations, so that we could suggest amendments and make observations that could be effective in improving it, we created a hostile and aggressive atmosphere that prevented the legislation from being studied in the best interests of Canadians."

Galvez said her colleague, Independent Alberta Sen. Paula Simons — who sided with the Tories to vote down Bill C-48 at committee — was "harassed" to vote a certain way.

Tkachuk defended the committee's work and the report it produced.

"This was not a waste of time. This was the Senate at its best," he said of the committee's travels.

He said the bill, which would ban tankers capable of carrying more than 12,500 metric tons of oil from an area that stretches from the northern tip of Vancouver Island to the Alaska border, is "so egregiously bad that it should be stopped in its tracks."

"Your committee has concluded from the varied and quite passionate testimony put before it, from a broad range of witnesses who appeared in Ottawa, British Columbia, Alberta and Saskatchewan, that Bill C-48 is both divisive and discriminatory," Tkachuk said.

He said the legislation, which does nothing about oil tanker traffic in Eastern Canada, serves only to bolster a growing Western Canadian separatist movement.

"The feeling of resentment, I can tell you, is palpable and any legislation that pours fuel on that particular fire should not be allowed to proceed," Tkachuk said.

He said the bill will cost "us all," as it imperils the future of Alberta's oilpatch and conventional oil development in Saskatchewan — two major economic drivers for the Canadian economy.

If enacted, the ban would frustrate future pipeline projects like the now-defunct Northern Gateway project, or the proposed Indigenous-led Eagle Spirit pipeline.

"Your committee strongly maintains that targeting one region of Canada for economic punishment is unconstitutional and destructive to the fabric of Canadian federalism," Tkachuk said.