Norwegian Air International plans to respond to a court challenge by aviation workers against the US government decision to give the Irish-registered carrier a permit.

The airline began services from Ireland to New York state and Rhode Island this month, but airline unions have petitioned a court to order the US department of transportation to end its permission to fly there.

While the case is against the US government and not Norwegian, the airline has the right to make its own submission and it signalled on Monday that it intended doing this.

“Norwegian is finalising a submission in response to the unions’ claims but it is widely recognised that these are tired and false allegations,” a spokesman said.

“Just this weekend, the US department of transportation itself reiterated that the unions’ claims are at odds with information in the administrative record and that Norwegian satisfied the requirements for an air carrier permit.”

Unions representing 100,000 members, including the Air Line Pilots’ Association and Association of Flight Attendants–CWA, claim that Norwegian’s Scandinavian parent registered it in the Republic to avoid labour protections and to hire crew on low-paid contracts, thus driving down US air crew wages.

However, the department of transportation’s response to the unions’ claims points out that pilots actually left US legacy airlines to join Norwegian because the wages and benefits it offered were better.

The department argues that Norwegian’s entry to the market could improve pilots’ and air crews’ conditions as it is likely to boost demand for their services.

“Information before the department of transportation showed that, between 2006 and 2014, the overall number of pilots employed by Norwegian long haul creased from 196 to 978, and was predicted to more than double between 2014 and 2017,” it says.

The submission states that job numbers in the US aviation industry actually fell by 25 per cent between 2001 and 2009, while the sector was only profitable in one of those years.

The department dismisses the unions’ claims that Norwegian’s entry to the US will damage their members by driving down wages as “ speculative”.