Liberal Leader Dwight Ball. (CBC)

The opposition parties are calling on the province to release a key piece of information related to the Muskrat Falls hydro project.

The Newfoundland and Labrador government confirmed Monday that it has received the so-called "decision gate three" numbers.

Those numbers will help put a price tag on the cost of the mega-project, as a decision is looming on whether to give it the green light.

When first announced two years ago, the project carried a price tag of $6.2 billion.

The province has since acknowledged the final cost will be higher.

Liberal Leader Dwight Ball says it's time to get all the information into the open.

"Somebody had to start this, we would have hoped that we could have had this discussion sooner than this," Ball said.

NDP Leader Lorraine Michael. (CBC)

The Liberals not only want the numbers, they also want to be able question witnesses during the Muskrat Falls debate in legislature — and call any experts on the project.

"What we feel here clearly represents, I think, what the public would want to see in a special debate on Muskrat Falls," Ball said.

The government says it will only make the numbers public after Manitoba Hydro International has done a review. That will likely happen around the end of the month.

NDP Leader Lorraine Michael wants them released now.

"The numbers are the numbers, so let us see them," Michael said.

"We all need them to do further analysis. MHI needs them but we do too."

No date has been set for the debate, but Premier Kathy Dunderdale has indicated it will happen sometime this fall.