Dave Hartnett, until last year the country’s top-most taxman, has got a new job – at Deloitte, the accountancy firm mired in a tax scandal for its handling of Vodafone and Starbucks accounts.

Deloitte’s response was, in essence, don’t worry, Mr Hartnett won’t have anything to do with tax and the UK. Instead, the company said, he would work “primarily” on tax regimes in developing countries.

That didn’t stop the firestorm from brewing, however. Margaret Hodge, chair of the Public Accounts Committee, accused him of “greed” and of “losing all sense of what is right”.

But Mr Hartnett may well have a case for feeling a little aggrieved. Why pick on him when he’s clearly following a well-trodden path?

FactCheck takes a look behind the revolving doors of Whitehall and the private sector.

In whose footsteps is Mr Hartnett following?

The Big Four accountancy firms – Deloitte, KPMG, PriceWaterhouseCoopers and Ernst and Young – all have form when it comes to hiring former public servants.

According to the Advisory Committee on Business Appointments (ACOBA), which confirms senior grade former civil service appointments to the private sector, at least 13 senior civil servants have moved from government to the Big Four in the last 10 years.

But the committee only needs to oversee appointments of a certain grade of former public servants. Which is why the KPMG partners, Alan Downey, Paul Kirby and Neil Sherlock, for example, wouldn’t have featured in those lists.

And when it comes to it, the civil service is happy to have them back. The aforementioned Mr Kirby is one such example – he was a senior partner at KPMG, then in February 2011 was appointed as David Cameron’s head of policy development. Until he went back to KPMG last January.

On top of this, there are secondments, such as Robert Edwards, senior manager for international tax and treasury at KPMG. His past includes a stint as policy advisor for the corporate tax team at the Treasury.

But the Big Four’s revolving doors have turned for watchdogs too.

John Griffith-Jones, formerly the senior partner at KPMG, will sit in the chair of the Financial Conduct Authority when it replaces the Financial Services Authority next year.

John Whiting, director of the Office of Tax Simplification, used to work at PwC.

Is there life outside the Big Four if you’re about to leave the civil service?

G4S can count a number of Whitehall alumni among its ranks.

The most high profile appointment is the former home secretary, John Reid, who is now a Labour peer. He was recruited by G4S in 2008 as a consultant.

In December 2011, G4S appointed a new director of probation and community services, David Griffiths. Before that, he was deputy director of justice policy at the Ministry of Justice.

A4e, the company most closely associated with the Work Programme, which we’ve FactChecked a number of times before, appeared happy to snap up Jonty Oliff-Cooper.

Mr Oliff-Cooper was appointed as director of policy and strategy at A4e in 2010. Before that, he was an aide to Steve Hilton, Mr Cameron’s former policy adviser, having joined the Conservative Party as a policy adviser in 2008.

Is it a problem?

Depends on who you ask.

The revolving doors have been seen as a a slippery slope when it comes to aspects of the Work Programme, which has faced accuastions of cronyism.

In the case of Mr Olliff-Cooper, who you may recognise from the reality show The Edwardian Country House (which was on Channel 4), it was pointed out that some time after he joined A4e, the founder of the company, Emma Harrison, was appointed as Mr Cameron’s “families tsar”.

Dean James was chief operating officer for the corporate IT directorate of the Department for Work and Pensions.

In June 2010, he was appointed as a CEO of Ingeus UK, which is half owned by Deloitte and is one of the biggest companies delivering the Work Programme.

Alan Cave was a director at the DWP overseeing the Work Programme, but he quit to join Serco, which delivers Work Programme contracts for the DWP in the Midlands and South Yorkshire.

Last year, during a debate on electoral registration in the House of Lords, Lord Reid asked: “Is the Minister aware that the best protection against misuse or fraud on cyber issues is biometric protection?” ┬áHe might have mentioned that G4S have a stake in the biometrics market, but didn’t.

The Public Accounts Committee raised concerns over the case of Mr Edwards, because he helped develop new rules on Controlled Foreign Companies at the Treasury. He then returned to KPMG to advise on how to use those rules.

Ms Hodge told the Committee that he also “wrote the rules” on the Finance Company Exemption, before going back to KPMG “where he is now a member of the team who advise about how to use those rules as an opportunity to pay less tax” in a clear example of “cases of poacher, turned gamekeeper, turned poacher again”.

The Advisory Committee ACOBA says it’s in the public interest for people with experience of public administration to move into business or other bodies, “and that such movement should not be frustrated by unjusitified public concern over a particular appointment.”

The rule is a two-year cooling off period, during which former public officials are banned from lobbying the government.

ACOBA also sets conditions. In the case of Mr Hartnett, who has also taken work with HSBC since leaving, he’s actually been told by the committee that he can’t work on UK-related matters at Deloitte.

Surely there’s some element of scrutiny?

Yes, ACOBA. It’s just that it’s not seen as being very effective.

Transparency International has said that it should be abolished and replaced with something with more teeth.

So has the Public Administration Select Committee. Last year, it published a report on ACOBA, and said that it lacked adequate powers and resources – it has no powers of enforcement. One of its recommendations was that it should be abolished.

As yet, the government hasn’t responded.