Qatar Airways insisted on Tuesday it would not take more deliveries of the widebody jet  Airbus A350s until the problem was resolved, as the surface below the paint was degrading unusually at an accelerated rate.

The Gulf carrier has fallen out with the European planemaker, warning last week that Airbus faced “industrial repercussions”.

“Qatar Airways continues to experience and has witnessed a condition in which the surface below the paint on some of its Airbus A350 aircraft has been degrading quickly,” an airline spokesperson said in response to a Reuters query.

The airline has grounded some jets “until the condition and root cause can be understood and corrected,” the spokesperson said, without disclosing how many aircraft were affected.

An Airbus spokesperson said the company was always in talks with its customers but that such talks were confidential.

The airline is the largest customer for Europe’s latest long-haul jet and has taken delivery of 53 out of 76 on order.