On 18 September 2017, it was announced by Eberhard van der Laan in an open letter to Amsterdam citizens that Kajsa Ollongren would take up his office as acting Mayor of Amsterdam with immediate effect due to ill health. Ollongren was succeeded as acting Mayor by Eric van der Burg on 26 October 2017 and by Jozias van Aartsen on 4 December 2017.