Both IAG and BA are suing SEPLA. Unsurprisingly, the action is being launched in the UK courts.
IAG - International Airlines Group - News Release=
IAG and British Airways have lodged a claim in the UK High Court against SEPLA, the Iberia pilots' union, and the International Federation of Airline Pilots Association in relation to the strikes that SEPLA undertook against the creation of Iberia's subsidiary Iberia Express in late 2011 and early 2012. This claim is not related to the recently announced restructuring of Iberia.
The claim is made under European law which provides that airline groups should be free to establish air services across Europe. IAG is seeking a declaration that its EU rights were infringed and British Airways is seeking damages because the strikes affected its business, causing it to incur financial loss.
British Airways is also seeking redress for the reputational damage it suffered because of false accusations made by SEPLA that British Airways misappropriated Iberia funds and that the strikes were intended to prevent the transfer of Iberia's business to British Airways.
Under EU law, any strike action against the establishment and provision of intra-European airline services must be justifiable, proportionate and non-discriminatory. Iberia's pilots suffered no changes in their terms and conditions and faced no redundancies due to the creation of Iberia Express but, directed by SEPLA, carried out strike action on 18 days between December 2011 and April 2012.