The bidder for the National Broadband Plan will have to invest €2.4bn in the project, according to the Minister for Communications.
Richard Bruton claims that will be the cost to Granahan McCourt over the lifetime of the 25-year contract.
The Minister for Agriculture Michael Creed said last week the company was only putting €200m in to match the State's €3bn investment.
However, Minister Bruton says the company's contribution is much larger.
"They have a responsibility under this contract for €2.4bn of the total cost of the project," he said.
"The State has a responsibility for somewhat the same sort, though part of the State's cost is a contingency, so may not be called upon.
"They have a responsibility under that contract to provide initial equity, of course, but working capital equity," he said.
All opposition parties are now calling for more clarity, with the government still citing commercial sensitivities around a contract that hasn't yet been signed.
Fianna Fail have said they cannot back the project in its current form.
The Sinn Fein leader Mary Lou McDonald has accused Michael Martin of "aiding and abetting" the National Broadband Plan controversy and said he has been playing "spectator politics" up to now.
Sinn Fein has urged the party to back a motion it is putting forward soon to give responsibility for the rollout of rural broadband to the ESB.