Eir has submitted a detailed plan to Government on how it could roll-out the National Broadband Plan for less than €1 billion.

The Eir chief executive, Carolan Lennon, told the Oireachtas Communications Committee on Tuesday that her company could deliver the plan for a fraction of the cost agreed with the preferred bidder, the Granahan McCourt consortium.

Subsequently, the Department of Communications requested a detailed note from Eir on its proposal - including its financial modelling and assumptions.

The plan was sent this evening - two days later than had been requested by the Department.

It is understood that Eir will not be making any comment on its plan until the Government has had an opportunity to consider its provisions in full.  

Eir has said it will not comment on whats contained in its detailed plan until officials there have had the opportunity to assess it. 

However, in her comments on Tuesday Ms Lennon said certain conditions included in the national tendering process would have to be stripped-out in order to reduce costs. 

One example of what Eir wants to remove is the requirement to establish a separate legal entity to administer the service - something the Department has said is crucial as it ensures transparency and compliance with State Aid rules. 

Eir has said it could also strip out €900m it would be due from the use of its poles - however the Department is understood to be concerned that this would present significant regulatory and competition law issues.

There is also an issue of trust between the parties. 

Eir's Chief Executive said her company told the Department that they could significantly reduce the cost but never heard back from officials.  

It is understood the Department contends the €1 billion was never raised by Eir in any of their numerous and lengthy meetings over several years. 

Last month, the Government awarded preferred bidder status for the delivery of the national broadband plan to a consortium led by US businessman David McCourt. 

The value of the contract is capped at just under €3billion.

Ms Carolan's statement on Tuesday led to Opposition calls for the Government to re-assess its plans.

In the Dail earlier this week, the Taoiseach Leo Varadkar decribed Eir's €1bn suggestion as a "big turnaround" given Eir had been a bidder in the original process and its tender document included a bid of €3bn. 

When the plan finally arrives, officials will seek to determine if it would comply with State Aid requirements and how any re-tender process would further delay the delivery of high-speed broadband to 540,000 homes and businesses in rural Ireland.