 Mr. Mihalache was the President's chief of staff – Head of Presidential Chancellery and the Head of Presidential Administration since December 2014, immediately after the election of Klaus Iohannis as President of Romania – and one of Klaus Iohannis' closest advisors after he became president.On 8 June 2016 Klaus Iohannis signed the presidential decree appointing Dan Mihalache as the Ambassador of Romania to the Court of St. James's, although voices from the Civil society expressed concern with Mihalache's appointment.In 2012 Dan Mihalache was discharged from the role as the Deputy Secretary General of the Romanian Government by the Prime Minister Victor Ponta as a result of Mihalache's comments regarding the warning raised by the Ambassador to Romania, Mark Gitenstein, against any modifications to the Romania's National Integrity Agency's law (whose main task is to ensure the performance of public dignities and positions in conditions of impartiality, integrity and transparency), which the Ambassador said could lead to a new set of discussions or even cancelling a proposed Romanian-American Strategic Partnership; Mihalache declared in an interview that he is not worried about the ambassador's warning and suggested that it may be better if the partnership didn't happen, considering who the director of Romania's National Integrity Agency is, leading to his dismissal by the prime minister.