The Green Party elects its leader, deputy leader and seven other senior positions every two years. The rules are that co-leaders will have one deputy, but if there is a single leader elected, they will have two deputies. The election process is also subject to balancing for gender. Incumbent co-leader Caroline Lucas announced on 30 May 2018 that she would not seek nomination and was therefore standing down. The other incumbent co-leader, Jonathan Bartley, announced on 1 June that he would run for re-election, in a job share with former principal speaker and current London Assembly group leader Siân Berry. Incumbent deputy leader Amelia Womack announced on 7 June that she would also run for re-election. Other candidates contested each of the elections.
Tim Young's application was rejected as he had insufficient nominations.
Leadership campaign
Berry said that, if elected, she would continue as a councillor in Highgate and a London Assembly member. Oliver Lewis, a Labour Party councillor for the same ward as Berry, said, "She must have known this was coming. They had a leadership website ready to go." Bartley and Berry released a detailed plan for their leadership on their website, promising a renewed focus on non-violent direct action, expanding election training to train the next generation of Green leaders, and to prepare the party for greater electoral success. Berry said that she would not be interested in standing for Parliament, if elected Co-Leader, but would use her increased profile to compete again for the London mayoralty. On 11 August 2018, The Times reported that on Holocaust Memorial Day, in January 2009, Shahrar Ali had made a speech comparing Israel's treatment of Palestinians to the Holocaust. In an article published on the Left Foot Forward blog, the Campaign Against Antisemitism described his speech as anti-semitic and an "offensive rant". Ali described the accusation as a "gross fabrication", telling the Evening Standard that it was "designed to stifle legitimate criticism of the Israeli government". The Green Party said that its initial handling of reports about Ali's speech in 2009 were inadequate and that it is seeking to revise procedures. The Green Party later clarified that no formal complaint of anti-semitism against Ali had been received.