The Minister for the Marine, Mr Fahey, has approved the Development Plan for the Corrib gas field.
Mr Fahey also gave his approval for an underwater structure on the continental shelf and an undersea pipeline between the gas field and Pollatomish at Broadhaven Bay on the Mayo coast.
The gas pipeline will feed into the Republic's proposed "ringmain" serving Dublin, Waterford, Cork, Limerick and Galway, through a link between Pollatomish to Craugwell in Co Galway.
The ringmain will link to the UK through twin interconnections between the Republic and Scotland.
The Department of the Marine will now sanction a foreshore licence for work in connection with the offshore section of the Corrib pipeline.
Yesterday's announcement by the Minister follows a recommendation by the Marine Licence Vetting Committee which last week approved the Corrib project on environmental grounds.
However, there are significant permissions yet to be achieved before the Corrib gas begins to flow.
These include approval from the Environmental Protection Agency (EPA) for an integrated pollution control licence; approval from An Bord Pleanála for the land-side terminal to be developed at Poll an Tómais; and approval from the Health and Safety Authority for the terminal.
Enterprise Energy Ireland (EEI), the gas field's principal developer, also requires a final consent from the Minister, after the pipeline and other facilities are in place, but before the first gas flows.
The first gas is expected to be delivered in January 2004. It is expected to contribute more than 850 cubic feet of gas over a projected lifespan of between 15 and 20 years.
In its first year of production the Corrib field could provide about 60 percent of the State's predicted demand.
Objectors to the project, including the Erris Inshore Fishermen's Association, have warned that irrevocable damage could be done to the environment of Broadhaven Bay.
However, in proposing to grant a foreshore licence, the Minister has listed a number of conditions in relation to the construction work.
These include:
An environmental management plan is to be drawn up for the approval of the Minister and is to be agreed and in place before construction work begins;
The methodology of pipe-laying is to be drawn up in consultation with Dúchas and agreed with the Department of the Marine before laying begins;
The setting up of an environmental monitoring group with local interests involved.
Meanwhile, Dr Jerry Cowley, who is standing as an independent general election candidate in Mayo, has called for a renegotiation of the State's deal with developers Enterprise Energy Ireland (EEI) on the Corrib gas field, following its multibillion-euro takeover by Royal Dutch/Shell.
Dr Cowley maintained the price paid for the company indicated the gas find had been grossly undervalued in information presented to Government.