A budget report released on Thursday says that the Liberal government overpaid for the Trans Mountain pipeline and stands to lose billions if construction doesn’t move forward soon.

The review, conducted by the Parliamentary Budget Office, estimates the existing line and future expansion project are worth between $3.6 and $4.6B.

Ottawa paid $4.4B for Trans Mountain in August 2018 after it failed to find another private-sector buyer for the pipeline, Trans Mountain Expansion project and related assets.

One of the significant findings in the PBO report is that delays in construction are continuing to devalue the project.

Every year that passes without the line being built, the value of the deal drops by $700M. A 10 percent increase in construction costs could push that deficit up by $450M and if the perceived risk of the project also rises, the government would lose another $1.3B.

In the worst-case scenario, where the Trans Mountain pipeline never goes ahead, the value of the pipeline with no revenue-generating capacity is between $1.8 and $2.8B.

The Alberta government says the federal government paid within the range that was given for Trans Mountain.

“It depends on how you look at it, I think,” said Energy Minister Margaret McQuaig-Boyd. “It was good to keep the pipeline moving and it’s a decision that they made at the time with the facts they had. We’re looking forward to the last decision on February 22 and we’ll see where it goes.”

The PBO report also reiterated the benefits of the expansion project where it would help to reduce the differential between WCS and WTI.

It’s unclear how much a completed expansion project could affect that figure.

The Federal Court of Appeal quashed the federal government’s approval for construction of the Trans Mountain project on August 30, 2018.

It ruled that the National Energy Board’s review process was flawed and ordered a new review, one with a stronger emphasis on Indigenous consultation. The new report is due on February 22.

(With files from CTVNews.ca)