Christopher Pyne
(Image: AP/Andy Wong)

While Christopher Pyne's new gig with EY (formally Ernst & Young) warrants an examination of the failure of the purported ministerial code of conduct to halt the revolving door between the ministerial wing and the private sector, any Senate inquiry should focus on a much bigger issue: scrutinising the big four accounting firms' rapidly growing role in government.

That the government has been handing ever more money in recent years to private companies for management consultant services -- i.e. the kind of services traditionally provided by the Australian Public Service -- seems undeniable. An Australian National Audit Office (ANAO) report in late 2017 showed a marked increase in consultancy spending under the Coalition. Private analyses like those done by Michael West, who has been the most assiduous investigator of the role of the big four in tax avoidance and government contracts, also shows surging revenue for consultants.