[1] Before becoming an MSP, Marra worked for Oxfam and the Leverhulme Research Centre for Forensic Science at the University of Dundee.

[2] In the 2015 United Kingdom general election, he contested Dundee West but lost to Chris Law from the SNP.

In November 2020, Marra was confirmed as a candidate on Labour's regional list for the North East, coinciding with his sister Jenny Marra announcing that she would not seek re-election to the Scottish Parliament.

[4] On 8 May 2021 Marra was elected as a Member of the Scottish Parliament (MSP) for North East Scotland.

[8] In April 2023 it was announced he would take on the role of Shadow Cabinet Secretary for Finance [9] Marra backed the UK Government’s decision to introduce means-testing for the Winter Fuel Payment, voting in the Scottish Parliament against calls to reverse the decision.