Duty free rule changes after the UK leaves the EU represent a hammer blow to Belfast International Airport, its managing director has said.
It will make air travel in the north less competitive than the rest of the UK and the Republic, Graham Keddie added.
The Treasury on Friday announced changes which will come into force from January, including extending duty-free shopping to passengers travelling to the EU.
Passengers will be able to buy duty-free alcohol and tobacco products in ports, airports, international train stations, and aboard ships, trains and planes, it added.
Mr Keddie said: "The government has once again shown a complete lack of awareness for the jobs and businesses on the line in the aviation sector.
"Our industry is weathering the worst crisis in the history of civil aviation, it can scarcely afford another hammer blow like this."
The Treasury also said that it will be ending tax-free sales in airports of goods like electronics and clothing for passengers travelling to non-EU countries.
It said this followed concerns the concession was not always passed on to consumers in the airport, and that in some instances the tax-free goods were being brought back into the country by UK residents, putting high street retailers at a disadvantage.
Mr Keddie added: "If these new rules come into force, Northern Ireland will be the only part of the UK that doesn't benefit from duty free for EU flights.
"This will put Northern Ireland airports at an even greater disadvantage to their Republic of Ireland counterparts, in addition to the ongoing burden of air passenger duty."
He said the British government was needlessly harming the revenue of retailers and airports.
"Passengers will be disincentivised from making purchases as they travel through the UK.
"By extending the duty free sales to EU countries from Great Britain only, it puts Northern Ireland's airports at a complete disadvantage, and instead of achieving additional revenue for the UK Treasury, passengers will choose to fly out of neighbouring airports, and the sales and job roles will be lost to the Northern Ireland and UK economy.
"I strongly urge the government to reconsider, review its proposal and act in partnership with its once world-beating aviation industry to secure jobs, businesses and livelihoods across the country."
Full guidance on duty and tax-free goods in Northern Ireland is expected to be published before the end of the Brexit transition period, in line with British government commitments in the Northern Ireland Protocol.
A Treasury spokesperson said: "We recognise the challenging times facing the aviation industry, which is why we've supported the sector throughout the pandemic, and continue to do so with schemes to raise capital, flexibilities with tax bills, and financial support for employees.
"We're making use of the end of the transition period to bring our personal duty and tax systems in line with international norms.
"Our removal of tax-free sales follows concerns from industry that the benefit is not consistently passed on to consumers."
