Despite his impressive CV as Liberal National Party campaign director in Queensland – which delivered a landslide to Campbell Newman in 2012 – and stints working as a gun for hire overseas including for London Mayor Boris Johnson, the extremely private Senator McGrath flew below the radar in his first 12 months in Canberra.
In the context of the input sentence, determine the relationship between 'Campbell Newman' and 'Mayor'.
Options: position held, parent organization, legal form, stock exchange