Four US Congressmen have introduced legislation attempting to block plans by an airline to introduce a new route between Cork and Boston.
Low-cost airline Norwegian Air last year announced plans to launch direct flights from Cork to the US, with four to five flights a week.
The Irish Examiner reports the airline had intended to start flights in August.
The US Department of Transportation made a tentative decision to grant a permit to Norwegian Air International earlier this month - a decision the four Congressmen say is "short-sighted".
The proposed legislation is aimed at permitting Norwegian Air operating between European countries and the US unless the "carrier complies with basic, fair US or European Union labour standards".
The bipartisan bill was introduced by Democrats Peter DeFazio and Rick Larsen, along with Republicans Frank LoBiondo and Lynn Westmoreland.
In a statement on the bill, the four politicians say that "NAI established itself in Ireland, where labour laws permit the airline to hire its pilots and flight attendants on individual employment contracts under non-European law in order to cut costs.
"NAI’s overt practice of labour forum-shopping violates our Open Skies agreement with Norway and the European Union and gives it an unfair competitive advantage in the transatlantic market," they add.
Representative Larsen said, “granting an air carrier permit to NAI would say to the world that the US rewards other countries that break their commitments to protecting workers".
Last week Norwegian Airlines released a statement about its Irish operations, saying "opponents claim that Ireland is simply a 'flag of convenience'. In reality, NAI is headquartered in Dublin with 80 employees, 37 aircraft registered in Ireland, and already operates flights to and from Ireland, with many more routes planned".
The company is also planning to introduce a Cork to New York route in 2017.