PARIS (Reuters), – A British minister offered mediation in a dispute between Airbus Airlines and Qatar Airways about costly flaws found on A350 passenger planes by the airline maker, according to three sources familiar with the matter.

Gerry Grimstone the Investment Minister offered to host a meeting of the sparring groups. Before the rows escalated on Thursday with Airbus promising to use an English court procedure to obtain an independent legal evaluation.

When Reuters asked the UK about its previous mediation offer, a UK official responded that it had confirmed the request and noted “the importance Qatari and Airbus investments to the UK”.

Airbus and Qatar Airways declined to comment. As the parties move toward a legal battle over the effects of skin defects on the jets, people who are familiar with this situation say there is little indication that they will accept the offer.

Qatar Airways claims it was ordered by regulators to ground 20 A350 aircraft over damage to an anti-lightning layer. The airline insists that there is no root cause and it cannot determine if safety has been compromised.

Airbus insists that they understand the causes and accused Gulf carrier Airbus of misrepresenting it as a safety problem and refusing a repair plan.

According to industry experts, the public’s reaction to the worsening dispute between two key aviation players is unheard of. Last week, Reuters revealed that other airlines also had reported problems. However, none have grounded the long-haul plane.

Qatar Airways did not respond to the Airbus legal notice, published late Thursday evening ahead of weekend in the Gulf.