[3] Following a party investigation, the claims were substantiated, McDonald issued an apology on 6 March 2018, announcing he had now left the SNP and would sit in the Scottish Parliament as an Independent.

Twelve days later his colleagues elected him as vice-convener of the housing and environment committee and he was appointed the deputy leader of the SNP group on the council.

As the Scottish National Party had already won all ten constituency seats in the region, it came as a surprise to McDonald, who famously appeared at the declaration wearing jeans and a T-shirt.

In addition, he served on a number of Cross Party Groups (CPGs) including Oil & Gas, Carers, Epilepsy and Mental Health (which he co-convenes).

Following the death of Brian Adam in April 2013, Mark McDonald was selected as the SNP candidate for Aberdeen Donside and resigned his seat as a North East Scotland Region MSP to fight the by-election.

[15] A keen runner, McDonald announced in July 2019 that he was running the Chicago Marathon in October the same year to raise money for a local charity in the North East of Scotland.