At a special convention on whether to support the Treaty of Lisbon on 19 January 2008, the party voted 63.5% in favour of supporting the Treaty; this fell short of the party's two-thirds majority requirement for policy issues. As a result, the Green Party did not have an official campaign in the first Lisbon Treaty referendum, although individual members were involved on different sides. The referendum did not pass in 2008, and following the Irish government's negotiation with EU member states of additional legal guarantees and assurances, the Green Party held another special convention meeting in Dublin on 18 July 2009 to decide its position on the second Lisbon referendum. Precisely two-thirds of party members present voted to campaign for a 'Yes' in the referendum. This was the first time in the party's history that it had campaigned in favour of a European treaty.