One of the private backers of the Waterford runway extension says the taxpayer will get value for money from the project.
Dublin Aerospace founder Conor McCarthy believes Waterford Airport could attract one flight a day to the UK year-round, and have charter flights to destinations such as Palma and Malaga during summer.
Shane Ross's decision this week to give €5m of funding to the project has been heavily criticised, but Mr McCarthy told the Irish Independent that the payback to the taxpayer could be rapid.
He said that a 2017 report prepared by economist Jim Power suggested that Waterford Airport could attract 300,000 passengers a year, contributing about €33m to the economy, with the south-east benefiting most.
Mr McCarthy, a former Ryanair executive, is the executive chairman of aircraft maintenance firm Dublin Aerospace. He is also a co-founder of AirAsia.
Since 2018, he has been chairman of Stobart Air, the Dublin-based airline company whose operations include the Aer Lingus Regional service. Stobart Air is part of Connect Airways, which is backed by Virgin Atlantic. Connect Airways is awaiting EU clearance to acquire Flybe.
Waterford hasn't had any scheduled passenger services since 2016. Its main operations currently comprise search and rescue services, with one of the Coast Guard helicopters based there.
The local councils from Waterford, Kilkenny and Wexford are providing an additional €2m in funding towards the runway extension. Private backers including Mr McCarthy, Glanbia, Coolmore Stud and Dawn Meats are stumping up €5m.
The current runway at Waterford is too short to accommodate jets such as the Boeing 737, which is the mainstay of Ryanair, or the Airbus A320 that's used by airlines such as EasyJet.
Mr McCarthy said he hoped the new runway could even be operational in time for summer 2020 - an ambitious timetable.
He said the first airline to start services at Waterford Airport would get "significant marketing support".