In December, the CAA’s chief executive, slammed Jet2.com: “ADR is good for UK consumers, which is why it is extremely disappointing that Jet2, one of the UK’s largest airlines, has so far inexplicably and persistently refused to sign up, denying their passengers access to an independent arbitration service,” added Haines.

The CAA also singled out Aer Lingus and Emirates as having not signed up to the initiative, which it describes as “ensuring passengers get access to an independent complaints service”.

The CAA calls ADR a “fair arbitration service”, which can legally resolve disputed complaints fairly and efficiently, limiting the need to go to court.

But Jet2.com has now responded, saying it considers the CAA’s criticism is “unjustified and unfair”, and listed the following reasons:

• As a matter of law, participation in ADR is entirely voluntary, and this is recognised and accepted by the CAA. If entering into a scheme is optional, it is wrong for someone to be criticised for not entering into it.

• Jet2.com has not ignored the availability of ADR but it has instead investigated the pros and cons of ADR, including meeting with CEDR, the leading provider of the ADR adjudication services, on more than one occasion. It was only after these evaluations that we decided that ADR is not in our customer’s interests or the interests of Jet2.com. We are not against ADR as such – Jet2holidays is a member of Abta’s very effective ADR scheme and is satisfied with the way in which that operates. But having carefully looked at ADR for passenger flight disputes, many of which involve complex factual, technical, operational issues and involved legal interpretation of EU regulations and decisions of the European Court of Justice, we do not think it is appropriate.

• It is true that some other airlines have decided to sign up to ADR. Not all airlines are the same, and many are not like Jet2.com and do not have industry-leading processes for dealing with complaints and claims for compensation. Our customer service has been recognised in the many prestigious consumer awards we have received. Some other airlines may not have carried out the careful evaluation which we have, so did not understand the problems with ADR before signing up. But in any case, the mere fact that some airlines have signed up to an optional scheme should not be a basis for criticising an airline which considers it is not right to sign up.

• Jet2.com’s customers are able to raise complaints and claims with us and can expect a prompt response. For instance, we pay out valid EC261 flight delay compensation claims with industry-leading speed: valid claims are paid out on average within 14 days. If a customer is not satisfied, the CAA’s “PACT” team is available, and a customer can also pursue a claim in court if necessary. The CAA says its reason for pushing ADR is that PACT decisions are not binding on airlines. However, the number of Jet2.com complaints which get referred to PACT is tiny. On all of those referrals the CAA agreed with our assessment of the claims.

• Our analysis shows that ADR is not a good process for resolving disputed claims for EC261 compensation, which makes up around 90% of the claims which other airlines’ customers refer to ADR. This is in part because such claims involve the assessment of technical, operational and factual issues, as well as the interpretation of law, regulations and conventions, which are better suited to the expertise of the courts which can apply legal precedents set right across the EU. Nor are we satisfied that the CAA oversees the ADR providers adequately to ensure consistent and fair results for customers and for airlines.

• We are also concerned that the minimal fee for starting ADR encourages complaints that are not valid. An airline is then put to great cost dealing with the ADR claim. Worse still, a customer can lose the ADR but still go to the county court and claim again on a claim which has already been shown to be unmeritorious, putting the airline to yet further expense.

Jet2.com concluded by stating that it would keep ADR under review, but as matters stand “does not think it would serve our customers’ interests or the interests of Jet2.com”.