Four U.S. lawmakers proposed a bill on Thursday that would block Norwegian Air’s plans to introduce a new route between Cork and Boston, “unless the carrier complies with basic, fair U.S. or European Union labor standards.”

Earlier this month, the U.S. Department of Transport (DOT) gave tentative approval to the airline’s application for a foreign carrier permit, allowing it to begin offering international service to the United States.

The low-cost airline had intended to start flights in August.

The four Congressmen who introduced the bill opposing the plan have called the department’s decision “short-sighted,” reports NewsTalk.

Democrats Peter DeFazio and Rick Larsen, and Republicans Frank LoBiondo and Lynn Westmoreland are behind the bipartisan bill.

A statement released on the bill says: “NAI established itself in Ireland, where labor 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 labor forum-shopping violates our Open Skies agreement with Norway and the European Union and gives it an unfair competitive advantage in the transatlantic market.

“‘Consumers may purchase tickets on Norwegian.com and they may board planes marked Norwegian in big bold letters, but this airline is ‘Norwegian’ in name only. The DOT record shows that Norwegian Air International is headquartered in Ireland and employs contract crews based in Thailand to circumvent Norway’s fair and strong labor standards. It’s a virtual airline set up to undercut competition by exploiting cheap labor. Our bipartisan legislation sends a strong message to DOT—we must stop this race to the bottom, and protect the open and fair transatlantic aviation market,’ said DeFazio.”

However, the airline has repeatedly stated that it will hire US and European pilots and crew for its transatlantic flights.  

Norwegian Air issued a statement opposing the legislation that it called a "last ditch attempt to derail the approval." 

"NAI's application is supported by scores of U.S. airports, communities, travelers, travel, tourism and business interests," the airline said in a statement.

The statement addressed 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 transportation department is asking for additional comment through May 13, before it finalizes its approval, USA Today reports.

The DOT has ruled that, as part of its tentative approval, the airline is financially and operationally fit to fly, and that Irish safety oversight meets the requirements of the Federal Aviation Administration.