to organise this airspace uniformly, with air traffic control areas based on operational efficiency, instead of national borders. Also, there were plans to integrate civil and military air traffic management. The framework regulation that sketched the working methods of the SES, and specific regulations on air navigation, airspace and equipment, were adopted on 11 December 2003, and entered into force as Regulation (EC) No 550/2004 (Service Provision Regulation) on 20 April 2004. There are discussions about enlarging the initiative to cover the Balkan and Mediterranean countries. Gibraltar issue (2000–2020) One report from the British Parliament, dated 2000, reported that Spain blocked the inclusion of Gibraltar Airport in the Single European Sky, meaning the whole package was suspended. Due to Brexit, formally completed on 31 January 2020, this stumbling block was removed. SES-I (2004–2009) The first SES legislation (SES-I) has been viewed as 'a real breakthrough', as is stimulated progress in harmonisation in air navigation service providers (ANSPs), the establishment of national supervisory authorities and EU competences over certification of these services. However, progress was slow in the next two years; the establishment of functional airspace blocks (FABs) was disorganised, little progress was made in improving cost efficiency, growing air traffic threatened capacity, and with tackling climate change emerging as a political priority, European aviation's emissions had to be mitigated. In response to strong demands from the industry, EU member states and other stakeholders, the Barroso Commission appointed a new high level group to develop a more detailed regulatory framework in November 2006. The group published its report in July 2007; it contained 10 recommendations, including making the EU the primary regulator of European aviation in order to set performance targets, safety requirements, introduce economic regulation of ATM services, incentives for ANSPs to achieve their objectives, and streamlining the implementation of FABs. Eurocontrol would provide the EU with technical support for regulations, safety regulation would be delegated to the European Aviation Safety Agency (EASA), and member states would be urged to hurry up with their commitments to implement the defragmentation of airspaces. SES-II (2009–2012) On 21 October 2009, a revision of the SES regulations called SES-II was adopted, which entered into force on 4 December 2009. Focus is here on four areas: The existing Single Sky legislation is sharpened to deal with performance and environmental challenges. The Single European Sky ATM Research (SESAR) programme is to provide the future technology. The