IATA has called on the European Union and the UK to provide clarity on how the bloc's proposal for a cap on flights would work in the event of a no-deal Brexit.
Under its planning for such a scenario, the European Commission in December proposed that any flights operated by UK airlines between the country and the bloc on 29 March 2019 would be allowed to continue for 12 months; however, it also said that those carriers would not be able to add new routes or increase the frequencies of existing services during the period.
"That current flight levels will be protected even with a hard Brexit is an important assurance," states IATA's director general Alexandre de Juniac. "But with two months left until Britain leaves the EU, airlines still do not know exactly what kind of Brexit they should be planning for."
His comments followed the failure of the UK government to gain parliamentary approval for its EU withdrawal agreement on 15 January. It is unclear how the country will now proceed, but the default legal position is for the UK to leave the bloc on 29 March with no deal on the future relationship.
"There is legal and commercial uncertainty over how the Commission's plan to cap flight numbers will work," notes de Juniac. "In the small window remaining before Brexit, it is imperative that the EU and UK prioritise finding a solution that brings certainty to airlines planning growth to meet demand and to travellers planning business trips and family holidays."
In December, airports body ACI Europe suggested the proposed cap on UK airline services "would ultimately result in the loss of 93,000 new flights and nearly 20 million airport passengers on the UK-EU27 market".
The UK government has consistently expressed a desire for air connectivity to be unaffected by any Brexit scenario.
Under a no-deal scenario, the UK could exit the EU and immediately become a "third party" country, negating a raft of agreements on air services.