PHOTOS - Ryanair 2013 Charity Calendar slideshow

Irish owned low budget airline Ryanair is being prosecuted by consumer watchdogs in Spain over the production of their 2013 calendar featuring female cabin crew in bikinis.

Consumer groups in Spain's Malaga province believe the calendar is offensive and exploits female employees. The case is set to be heard before a three-judge panel on April 30.

The consumer group’s lawyer Antonio Castillo will ask the court to rule that the public use of these images is illegal.

Ryanair has complied but argues that the images are not sexist and that the members of staff portrayed had volunteered to produce the material, report the IBTimes.

The calendar is sold on all Ryanair flights for $12 and all proceeds go to the Polish TVN Foundation, which helps children suffering with cystic fibrosis. The calendar launched in October 2012 and had sold 7,000 by November, from a total run of 10,000. They expect to raise $128,508 for the charity.

This is the not the first time that Irish owner Michael O’Leary has had to deal with complaints about sexist business practices. At a press conference in Germany, in 2008, Ryanair hinted at a transatlantic service structure along a dual-service model; low-cost economy and high-quality business seats. It’s unfortunate working title was “Beds and B***hes”. The video of the press conference went viral on YouTube and received a cold public reception.

Also in 2012 the UK Advertising Standards Authority (ASA) forced Ryanair to stop using an ad with the image of an airline hostess in a provocative pose, including the tagline, “Red hot fares and crew.” The ASA petition, signed by over 10,000 people, labelled the advert as “sexist.”

Here’s footage of the Ryanair photoshoot released for the promotion of the 2013 calendar: