Economy Minister Dr Caoimhe Archibald stated that the refusal to provide relief from Air Passenger Duty poses a threat to the viability of the new air link.
The British Government has officially confirmed it will not grant an exemption for the scheduled service connecting City of Derry Airport with Dublin Airport.
Officials in London acknowledged the strategic value of the connection and its potential to boost economic activity across the North West region.
However, they maintained that the tax obligation remains in force because island air access is already exempt from duty in southern Ireland.
Dr Archibald argued that the existing relief for island routes creates an unfair disparity compared to mainland destinations.
The Northern Ireland Executive has not yet secured a formal review of the decision or proposed alternative measures.
Further details regarding the Department for the Economy's position are expected to be shared through official channels.
Media outlets covering the Department for the Economy can reach the duty press officer at 028 9037 8110.