Ryanair has begun an appeal of a High Court ruling that three pilots did not defame the airline.

In December 2017, Ryanair lost a defamation case it had taken against the pilots, John Goss, Ted Murphy and Evert van Zwol, in relation to an email issued in 2013.

The three were involved in the Ryanair Pilots Group, which Ryanair alleged was seeking to unionise pilots at the airline.

During the 27-day trial, Ryanair claimed the three men had maliciously circulated the email in question to 2,289 pilots in 2013 and that it was part of an ongoing effort by the RPG to unionise its pilots.

Ryanair had argued that the email falsely implied that Ryanair management had misled the market and facilitated insider dealing, among other things.

While the jury found the email had wrongly implied that Ryanair had engaged in market manipulation, it did not find any malice against the three defendants, which meant that the airline's defamation claim failed.

The court also ruled that the email did not imply other wrongdoing as alleged by Ryanair.

The pilots' lawyers had also argued that qualified privilege applied where a statement published to someone with an interest in receiving such information, as long as it is not motivated by malice.

During the course of the case, while faced with the threat of a series of pilot strikes, Ryanair reversed a 30-year policy and conceded union recognition.

This morning, Ryanair's grounds of appeal were outlined by Senior Counsel Martin Hayden.

He told the Court of Appeal that the trial judge had erred in making rulings on matters that would properly be issues for the jury to decide, and in failing to discharge the jury. 

He said the trial judge had also been wrong to find that the author of the disputed email Martin Duffy had not been an agent of the defendants, which could have been significant in relation to proving vicarious liability for malice on the part of the defendants.

Mr Hayden criticised the decisions of the trial judge to find that the defendants had not breached their discovery obligations, and to expunge some of the evidence of Ryanair employee Darrell Hughes regarding members of the RPG agitating with Ryanair investors. 

He also argued there had been an erroneous finding in relation to whether qualified privilege arose when the email was disseminated to more than 2,000 recipients, some of whose identities had not been confirmed.

He noted that 514 recipients had not been identified and that the defendants had failed to prove that those 514 people had the necessary interest in being informed about allegations of market manipulation required to establish qualified privilege. 

The defence submissions are expected to commence tomorrow.

The case before Ms Justice Maire Whelan, Mr Justice Seamus Noonan and Mr Justice Robert Haughton is expected to continue for two more days.