CALGARY -- The president and CEO of Trans Mountain announced Friday that the cost to build the pipeline expansion will be more than initially thought.

Ian Anderson says it will cost $12.6 billion, a significant increase from the three-year-old estimate of $7.4 billion.

To date, the company has spent $2.5 billion in respect to the project, with consideration for the impact of delays and the resulting additional regulatory process.

"Today’s Trans Mountain expansion project has seen significant changes, enhancements and improvements since it was originally envisioned in 2009, and first introduced to the public in 2012," said Anderson. "The project has set new standards for Indigenous participation and inclusion – with 58 signed agreements worth over $500 million."

Finance Minister Bill Morneau says the project is now a better one and it’s moving forward in the right way.

"The Trans Mountain expansion project will be an important driver in Canada’s transition to a cleaner economy. Every dollar the federal government earns — from the annual corporate tax revenue estimated at $500 million as well as any profit from an eventual sale — will be invested into clean energy projects that will power our homes, businesses and communities for generations to come."

Anderson says more than 2,900 people have been hired and, at peak construction, that number will reach 5, 500. The project is expected to be in service by December 2022.

Opponents have attacked the greenhouse gas emission and oil spill risks of the pipeline project. Four first nations who lost a court challenge earlier this week to stop the project have 60 days to appeal to the Supreme Court.