Rail chiefs in Ireland have sought permission to press ahead with a €2.5bn (£2bn) Dart Underground in Dublin with work expected to begin within two years.
An application lodged with planning authorities maps out the proposed 7.6km long twin tunnels to be bored under the city centre in an attempt to treble the number of rail passengers.
The project will connect the Northern and Kildare rail lines, with underground stations built at Spencer Dock, Pearse Station, St Stephen’s Green, Christchurch and Heuston Station. A new overground station would also be built at Inchicore.
Transport minister Noel Dempsey refused to disclose how much funding the Government would have to contribute to the public-private partnership scheme.
The government will apply to the European Investment Bank - which recently pledged €500M (£409M) towards the Metro North project - for some of the financing.
Potential private backers have until July 20 to express an interest. Investors would take a share in profits under the plans.
“There has already been significant interest,” Dempsey’s spokesman said.
Under the ambitious proposals, Dart Underground will link all of the capital’s rail systems - Dart, Commuter, InterCity, Luas and Metro - to form for the first time a fully integrated rail network.
The plans are being submitted under the government’s Transport 21 investment programme.
The work involves building 8.6km of new railway - 7.6km of which will be in tunnels - from the CIE Inchicore Works to tie into the Northern mainline, south of East Wall Road and north of the Docklands area.
Iarnrod Eireann said construction, involving two boring machines tunnelling under the city at an average depth of 24m, would be completed and the system up and running by 2018.