 On 25 September 2018, he announced that he had left UnHerd.In September 2019, Montgomerie was appointed as "social justice adviser" to the Prime Minister in Number 10 Downing Street.On 31 January 2020, he said on the BBC's "Politics Live" that the role lasted until the election was called in November 2019 and that he was now in discussions with Boris Johnson regarding a new advisory role following Johnson's success in that election.