The €3bn State investment in the controversial National Broadband Plan has been labelled “the worst deal ever seen” after it emerged that the private operator chosen to deliver it will only invest €200m equity in it.

Opposition leaders and TDs lambasted the Government after it was revealed that Granahan McCourt’s investment will be just one-15th of the State’s, yet the consortium, and not the taxpayer, will own the asset at the end of 25 years.

Finance Minister Paschal Donohoe said the deal was “the best option open to the State” and urged the Opposition to say how they would do it better and cheaper.

“I believe it is the best option open to the State to deliver 100% coverage in a way that protects us from risk,” he said. “If the Opposition believes there is an alternative way, it is incumbent on them to spell it out.”

He was speaking after Agriculture Minister Michael Creed let slip that Granahan McCourt’s investment is far lower than the €974m estimate included in official Government documents released last week.

“My understanding is — and bear in mind we’re asking the company to build an infrastructure where the private sector won’t go — they’re putting in, I think, in the region of something shy of €200m,” he told Clare FM.

Despite his comments, Mr Donohoe, Tánaiste Simon Coveney, and Communications Minister Richard Bruton have all refused to confirm how much Granahan McCourt was contributing to the project.

Mr Donohoe refused to do so again when pressed by reporters at an event at Dublin’s Glasnevin Cemetery.

“I am not in a position to reveal what that figure is,” he said.

The reason for that is that we have negotiations that will begin to sign the contracts, which will take up most of this year. While those discussions are under way, I have to respect the confidentiality of the company and the contribution they are making.

However, Labour leader Brendan Howlin, Mr Donohoe’s predecessor as public expenditure minister, was scathing in his criticism.

He said the revelation about the McCourt contribution is “ shocking”.

“It is truly shocking and unacceptable if it was in the order of €200m versus a State investment of €3bn,” said Mr Howlin. “Absolutely unacceptable that, after that paltry investment, that they would own the asset forever more, and not the people of rural Ireland.

“On the face of it, it is the worst deal I have ever seen and it goes to the heart of politics trumping the taxpayer and the people.”

Mr Howlin said the Government must confirm the numbers and show people what they are paying for this “collapsed deal”.

“We have redacted pieces of information presented to us,” he said. “Let’s just take out the redactions. If it is greater than €200m, then let us know that. This is beyond a time when such important facts are withheld from the people who are paying it.”

Barry Cowen, Fianna Fáil’s spokesman on Public Expenditure and Reform, said Mr Donohoe is “taking the people for mugs” on the costs of the National Broadband Plan. He described the Granahan McCourt disclosure as ‘farcical’.

Mr Cowen also said Mr Donohoe’s sums do not add up and he has failed to outline how the Government will pay for the extra €1.5bn to cover the project’s cost.

“The Government’s continued refusal to disclose documents in relation to the input of Granahan McCourt in the NBP is an affront to the taxpayers,” he said.