Ireland's planning body has granted permission for a €200M (£171M) tunnel to be built under Dublin Airport, despite objections from Ryanair and a community group.

An Bord Pleanála has granted Dublin Airport operator DAA permission to construct a 0.7 km long twin-cell enclosed tunnel underneath one of the airport’s runways. It will be linked to the surface by ramps, portals, and light attenuation screen.

The tunnel is intended to enable airside vehicles to traverse the airport’s “crosswind” runway more safely and efficiently.

An Bord Pleanála’s appeals board approved the development on the basis that it would “not give rise to any unacceptable impacts on the amenities of the surrounding area or on traffic safety and convenience during construction and operation.”

It also determined that the development “would not present an unacceptable risk to water quality.”

The development was initially given the go-ahead by Fingal County Council in February last year.

However, airline operator Ryanair appealed against the decision by claiming that the development could not be “justified economically”.

It said that the development should be “subject to a cost/benefit assessment and consideration of alternatives, due to the significant costs associated with the development and the disruption that it would entail”.

It also argued that the extent of the proposed excavation to construct the tunnel is “considerable” and that the DAA’s Environmental Impact Assessment Report (EIAR) “fails to provide detail on the storage or disposal of this material”.

North Dublin-based residents’ group St. Margaret’s The Ward (SMTW) Environmental Designated Activity Company (DAC) appealed against the development on environmental ground.

It said that the measures proposed to mitigate the impacts of the development on the environment were inadequate.

After considering the submissions, An Bord Pleanála was satisfied that the main direct and indirect impacts of the development on the environment – such as dust, construction traffic, and surface and groundwater pollution – would be mitigated by measures set out in the DAA’s EIAR.

Speaking to The Irish Times following the decision, the DAA said: “The tunnel is required to improve access and safety on the airfield, allowing for the segregation of aircraft and vehicles, and the movement of vehicles to the west apron, which has been restricted since the opening of the North Runway in August, 2022.

“Access to the west apron is critically important to cargo operations, transit operations, general aviation, stand-by parking and contingency stands.”

The tunnel will be around 0.7 km long, with an overall alignment of around 1.1 km in length from top of ramp to top of ramp. It will be approximately 24m in external width, and approximately 5.5m in internal height from road to tunnel ceiling. It will be up to 17.5m below existing ground level.