Amidst the generally positive reactions generated by the 2005 European Union (EU)-Ukraine Summit, one Ukrainian commentator went as far as to call the occasion 'a leap forward to Europe'. The 'new' Ukrainian leadership, which had come to power following the 'Orange Revolution' roughly a year before, had been eager to stage a public event that would catch the imagination of its pro-European electorate. In discussions on possible EU enlargement, the case of Ukraine remained the most controversial accession, after Turkish membership. While the EU provided a constructive point of reference for Ukraine, because of its positive public connotations and through an articulated set of agreements and programmes, Brussels' policy line was reviewed, as a result of a transformed political environment in Ukraine. Memorandum of Understanding was signed on co-operation in the field of energy, aiming at integrating the Ukrainian energy market into the EU, thereby enhancing the state's energy security.