The Government has announced plans to extend the Dart line in Dublin to Balbriggan by 2022.

However the plan for the Dart underground, including a tunnel under Dublin City linking the existing northern line at Connolly Station with Heuston Station, has been deferred.

Minister for Transport Paschal Donohoe said the tunnel element of the underground project will be re-designed.

He said the tunnel as currently planned would have cost €3 billion.

Mr Donohoe said the Government’s overall capital plan for the years ahead, to be published next week, would contain other investments to expand the Dart service.

He said most noticeably this would involve extending the Dart to Balbriggan in north Co Dublin by 2022.

He said the capital plan would also provide for work to be carried out on electrifying other rail lines into Dublin including the link from Hazelhatch to Heuston Station as well as a stretch beyond Balbriggan to Drogheda.

The Minister said the re-design of the tunnel element of the Dart underground plan could take 1 to 2 years to complete.

He said the original Dart underground plan had been drawn up a decade ago when the country was in a very different position regarding growth projections and travel patterns.

He said the National Transport Authority had carried out a review of the business case and had now recommended to the Department of Transport that the Dart underground project be re-examined “in order to deliver the required rail connectivity in the capital city with a lower cost technical solution”.

Mr Donohoe said the Dart underground project was considered to be very important and would go ahead at some point in the future.

Mr Donohoe said since the very instigation of the Dart underground project about €40 million had been spent.

He said the planned compulsory purchase of land to the value of €122million will not now be going ahead.

Opposition parties criticised the decision to put the underground plan on hold.

Fianna Fáil transport spokesman Timmy Dooley said the decision was a “major setback for the greater Dublin area and the economy.”

“The Minister’s decision today puts Dart Underground off the radar until sometime beyond 2020.”

The Green Party accused the Government of having no vision for the future of Dublin or the country and said the move was a “body blow” for a rail system “already on its knees”.

Irish Rail said it welcomed the decision to upgrade existing Dart lines.