Air Passenger Duty on direct long-haul routes from Northern Ireland airports is to be cut.
The direct long-haul rate of APD will fall to the lower short-haul rate - £12 per passenger in economy and £24 for business and first class passengers, chancellor George Osborne confirmed earlier.
APD presently adds £60 to an economy fare and £120 to a business ticket.
“The government has taken proactive measures to protect the only direct long-haul service operating from Northern Ireland and with it the jobs of those who serve the Belfast route,” Osborne said in a statement.
“Northern Ireland faces a unique challenge in attracting traffic - including very valuable business customers - into its airports.”
However, the airline recently told MPs the £3.2 million it would pay in tax on the route this year made it commercially unviable.
The route is seen as vital for promoting trade and inward investment.