[2] The son of Iain and brother of Natasha, Rebecca and Calum, McNicol was raised in Thirdpart, West Kilbride and attended Ardrossan Academy.

[8][9] On 19 July 2011, Labour's National Executive Committee selected McNicol to become the party's next General Secretary under leader Ed Miliband.

It reported senior figures in the trade union movement were discussing replacement options for McNicol in his General Secretary role.

[18] A documentary made by Panorama,[19] and shown on the BBC, addressed these claims, which were subsequently the subject of High Court action, resulting in damages being paid both to the journalist involved, and to those Labour Party staff who had blown the whistle.

This leak took place after the decision was made not to submit the report to the Equality and Human Rights Commission's investigation into institutional antisemitic racism.

The report stated that WhatsApp message group transcripts published in the report showed that McNicol and members of his office failed to deal with anti-semitism cases, worked against the objectives of the leadership of the Party, worked against Labour's objective of winning the 2017 general election, and made offensive comments about Labour members, staff, and politicians.

The report went on to state that: 'The EHRC found evidence of political interference in the complaints process, with 23 instances of inappropriate involvement by the Leader of the Opposition's Office and others in the 70 files looked at.'

[26] More leaked messages from WhatsApp groups involving McNicol were released in Al-Jazeera's 2022 documentary series "The Labour Files".