Old Fella,
the primary prerequisite is to have been a former union 'heavy'
Get over yourself will you. Not even the Liberals believed that rubbish when they were saying it during the election campaign. Just because one has worked for a union or represented one at some stage, does not make them a Union Heavy.
I did an internship at a Union during my degree. Does that make me a union heavy?
And by the way, when working in a union you are dealing with negotiations, politics (internal and external), finance, law and social policy on a daily basis. Could you please indicate which of these is a poor precursor to a career in politics?