The Taoiseach has said that the Department of Communications has written to Eir to seek clarification on its CEO's comments yesterday that it could roll out the National Broadband Plan for less than €1 billion.
Leo Varadkar told the Dáil that this was a "big turnaround" and officials were seeking clarification from Eir on "whether this offer is real, if it stacks up".
"The company is now saying that it can do this project for a €1bn. And if that is the case then I am all ears and we have to listen to it," Mr Varadkar said.
"We need to know if this offer is real, if it stacks up. We need to know what kind of delay would be imposed on people in rural Ireland waiting for broadband if we went back to a new procurement process," he added, saying that a new process would be needed.
He was responding to Fianna Fáil Leader Micheál Martin who welcomed that the Government "was at least going to look at this".
Mr Varadkar also said that Eir's comments had raised many questions.
"One of the things that we will want to find out for example is how there can be such a big difference between the €2.7bn bid from Eir and this offer of €1bn now," he said.
"A concern that I have, and the Department of Communications has, is that a big part of that difference, it would be met by imposing higher charges on those 500,000 homes, farms and businesses in rural areas, that Eir would not be making up the difference," he added.
He said higher charges and fees to those customers would be "a serious problem for us".
Mr Martin said that documents have revealed a "cavalier approach" to the ballooning costs.
"In terms of those documents, on 27 September last year it was revealed that the costs went up €300m in a month, in one month," Mr Martin said.
He also said that Eir had rejected the Taoiseach's earlier comments that it would be passing houses and not cover maintenance costs.
Meanwhile, the ESB has told an Oireachtas committee that the removal of 300,000 customers from the "target market" for the National Broadband Plan meant that the number of customers available to connect to the network was significantly reduced.
The company's Head of Strategy and Innovation, Denis O'Leary, told the committee that this would have led to a reduction in revenue for the company.
"When the 300,000 premises were removed it had a very serious impact on the potential and the projected revenues that they would see over ten, 20, 30 years of the project and that is what made it really challenging," he said.
The ESB and Vodafone joint venture known as "Siro" dropped out of the bidding process saying there was no longer a business case for its participation.
The decision came a number of months after the Government controversially removed 300,000 homes from its original plan and placed them back into Eir's commercial rollout plan.
The plan aims to provide over 540,000 rural homes and businesses with fibre broadband.
Mr O'Leary told the committee today that removing such a large number of premises had a major impact on the design of the network.
He said when the intervention area was reduced by 300,000, it has a material impact on the project.
Mr O'Leary also told the committee that the ESB could not roll out the National Broadband Plan for less than €1bn.
He said it was an enormous project to provide high speed broadband to the most remote locations in the country where road access and connectivity are poor.
Additional reporting Aisling Kenny