[3] In 2002, she joined the Department for Culture, Media and Sport, working as principal private secretary to Tessa Jowell and on London's bid and preparations for the 2012 Olympic Games.

[4] From 2014 to 2016, MacNamara was Director of the Economic and Domestic Affairs Secretariat at the Cabinet Office,[3] where she coordinated government preparations for the 2015 United Kingdom general election.

[5] Speaking about the appointment, Sir Jeremy Heywood, the then Cabinet Secretary said: "She is a highly experienced civil servant who has worked in many senior roles across government.

"[5] A government minister is reported to have described her as "a perfect official, fair-minded, doesn't play games, will always try to get at the truth, capable of bringing sense out of five-sided talks".

[6] In February 2020 former special advisers called on MacNamara to defend the workplace rights of ministerial aides, amid further complaints about Cummings' behaviour.

MacNamara claimed during this time she tried repeatedly to raise the lack of personal protective equipment (PPE) designed for women’s bodies.

[13] It emerged in Sue Gray's report that MacNamara had provided a karaoke machine during one of the illegal gatherings in Number 10 on 18 June 2020, during the COVID-19 lockdown.

[16][17][5] In January 2021 it was announced that she would leave her job the next month in preparation for a move to the private sector later in the year, working for the Premier League.