The deal ending the Shannon stopover was described by local campaigners last night "as the worst possible outcome for Shannon airport".
Joe Buckley, spokesman for Signal, the Shannon workers lobby, said it was "a black day" for the west of Ireland.
"It is an appalling deal and the Minister should have walked away from it . . . The deal raises the prospect of no winter transatlantic services out of Shannon, and if year-round transatlantic services can't be maintained, we won't see US industry coming to the west of Ireland."
Mr Buckley cited an independent study forecasting that Shannon's transatlantic traffic will drop from 700,000 to 400,000 per annum under an "open skies" regime.
Opposition party TDs in the mid-west united in condemning the deal.
Independent Clare TD James Breen said: "It is a sell-out of the mid-west by Minister Cullen. It will have a seriously negative effect on jobs at the airport."
Labour's Limerick East TD Jan O'Sullivan asked: "How could this have happened, particularly in light of the thousands of jobs, particularly in multinationals, which depend on transatlantic flights? In addition, the lead-in time is wholly inadequate."
Fine Gael TD Pat Breen described the deal as "the worst of both worlds", forecasting that "airlines will use their Shannon obligation for the peak periods during the summer and ignore the airport for the rest of the time".
Last night, at a function in Spanish Point, Minister of State for Education Síle de Valera declined to comment on the deal, saying she still had to study its details. The other local Minister of State, Tony Killeen, was unavailable for comment.
However, Fianna Fáil Senator Brendan Daly said last night: "Shannon airport has faced down difficult times before, and I have no doubt that they will face it down again.
"It is a challenge for them, but this was inevitable because I don't think governments will be able to determine where people can and cannot fly to."
