[5][6] The issue of Nick McKim's citizenship was raised during the 2017–18 Australian parliamentary eligibility crisis while he was a sitting senator.

[8] The Home Office citizenship renunciation guidelines state that a person will cease being a British citizen after the date of registration.

[12] On 19 April 2010, Labor premier David Bartlett agreed to appoint McKim as a minister along with Cassy O'Connor as cabinet secretary.

[13] As a minister, McKim originally held the portfolios of Sustainable Transport and Alternative Energy, Corrections and Consumer Protection, Climate Change, Human Services, and Community Development: though he delegated responsibility for the portfolios of Human Services and Community Development to fellow Greens MP and then cabinet secretary Cassy O'Connor.

[15] Another Cabinet reshuffle, caused by Lin Thorp losing her seat in the Tasmanian Legislative Council elections and David Bartlett resigning from the assembly, then saw McKim sworn in on 13 May 2011 as Minister for Education and Skills, whilst retaining the three portfolios of corrections, consumer protection and sustainable transport.

[19] McKim won the preselection ballot comfortably, defeating Huon Valley Councillor Rosalie Woodruff, environmental lawyer Vanessa Bleyer and several other more minor candidates.

[20][21] The Tasmanian Greens announced at a press conference on 30 July 2015 that McKim had won the membership ballot to replace Christine Milne in the Senate.

[26] McKim served as Greens Co-Deputy Leader from 4 February 2020 to 10 June 2022 and in the following positions: Treasury, Finance & Economic Justice Immigration & Citizenship Digital Rights, I.T.