In August 2009, four Moldovan parties (Liberal Democratic Party, Liberal Party, Democratic Party, and Our Moldova Alliance) agreed to create the Alliance For European Integration that pushed the Party of Communists of the Republic of Moldova into opposition. On 28 August 2009, this coalition chose a new parliament speaker (Mihai Ghimpu) in a vote that was boycotted by Communist legislators. Vladimir Voronin, who had been President of Moldova since 2001, eventually resigned on 11 September 2009, but the Parliament failed to elect a new president. The acting president Mihai Ghimpu instituted the Commission for constitutional reform in Moldova to adopt a new version of the Constitution of Moldova. After the constitutional referendum aimed to approve the reform failed in September 2010, the parliament was dissolved again and a new parliamentary election was scheduled for 28 November 2010. On 30 December 2010, Marian Lupu was elected as the Speaker of the Parliament and the acting President of Republic of Moldova. After the Alliance for European Integration lost a no confidence vote, the Pro-European Coalition was formed on 30 May 2013.