Dave Hartnett

Dave Hartnett is the former Permanent Secretary for Tax in HM Revenue & Customs (HMRC) and as such was the department's Head of Tax. In a career spanning more than 30 years he was an investigator, a technical specialist and policymaker. He was also Vice Chairman of the OECD's Forum on Tax Administration.

Hartnett 'retired' in September 2012 at the age of 61 years, but has since taken on lucrative advisory positions with organisations working with firms into which he once oversaw HMRC investigations.

Through the financial revolving door

Advising Big Four accountancy firm

In late May 2013 it emerged that the Advisory Committee on Business Appointments (Acoba) and Prime Minister David Cameron had approved Deloitte's appointment of the former tax chief for a one-day-a-week consultancy position.

Hartnett has previously come under pressure over his 'sweetheart deals' with several big companies, including Deloitte client Vodafone - a deal which saw the firm pay only £1.25billion of an estimated £6billion due (the latter figure is disputed by Vodafone).

A spokesman for Deloitte told The Guardian:

Dave Hartnett will work as a consultant to Deloitte advising foreign governments and tax administrations, primarily in the developing world. He has significant experience in advising such countries on the development of effective tax regimes, necessary to ensure their continued economic growth. He will not work with UK companies or with HMRC.

Caveats were reportedly set by Prime Minister David Cameron on what Hartnett can and cannot advise upon while working for Deloitte.

HSBC

In early 2013 Hartnett was appointed as an adviser to banking group HSBC on financial risks and crime,alongside former Director General of the Serious Organised Crime Agency, Bill Hughes and former US deputy attorney general Jim Comey), soon after the bank was fined $1.9bn (£1.3bn) by US authorities for laundering Mexican drug money.