It's a bum rap. Grey men and women, boring bean counters. Audit has a sad image.

But the auditors are fighting back. Across the UK and abroad public auditors are contesting the stereotype, asserting a wider responsibility over how public money is spent and, in some cases, getting much closer to executive management than they have been before.

Breaking Out, a collection of essays from leading public auditors, argues that they must intervene earlier in decisions by departments and agencies, and stick around to check their recommendations have actually been adopted.

In it, Amyas Morse, head of the National Audit Office (NAO), talks about "intervening earlier to prevent failures from escalating". Reporting earlier in the life cycle of projects can prevent them "from snowballing into significant value for money failures" and he cites the NAO's early (and critical) studies of HS2 and universal credit – the Department for Work and Pension's major reform.

It's a sentiment shared with Margaret Hodge, chair of the Commons' public accounts committee (PAC) – and the main body in parliament for picking up and implementing NAO reports. In the introduction, she writes: "I don't just want the PAC to bark; we want to be a catalyst in permanently improving how the government does its business." Though this raises some tricky questions about the relationship of legislature and executive, MPs and civil servants.

That impulse – to translate value for money audit reports into action and improvement – is by no means confined to Westminster. It seems to speak, in the age of austerity, to a strong urge to make spending more effective, and doubt that mainstream managers and the politicians they answer to lack capacity, especially financial literacy.

In Scotland, the auditor general Caroline Gardner insists that her professional colleagues have to become more proactive, pointing out the long-term implications of spending decisions, and blowing the whistle if they think they have been undercooked. Auditors themselves, while insisting government accounts become more transparent, have to write and speak more clearly and comprehensibly.

John Doyle, auditor general of the Australian state of Victoria, says accountants in the public sector must go beyond their former role of sweeping up and take responsibility jointly with managers and parliamentarians in improving performance.

In Canada, auditors were brought in to help design the stimulus package introduced after the 2008 crash – and in Ottawa the boundary between consultancy and audit is permeable.

The core job of an auditor remains independent verification that public money is being spent lawfully and effectively. But audit isn't inoculation. The accountants can't just sign the accounts and leave it there.

In emerging economies, where corruption if rife, auditors have not only to collaborate with and perhaps lead anti-bribery campaigns but, according to Pamela Monroe-Ellis, auditor general of Jamaica, "use audit to engage and educate the public, who don't appreciate what constitutes a corrupt or unethical act".

Auditors can't avoid looking at how services are delivered once spending decisions have been made. "Downstream" lie contractors and the array of services outsourced to private firms. Auditors are supposed to "follow the money", Professor Ron Hodges of Birmingham University and the Association of Chartered Certified Accountants' head of public sector Gillian Fawcett argue in their essay. On that trail auditors ought to start examining the performance of firms such as Serco and G4S. Private sector auditors may be responsible for their company accounts, but the work they do for the public sector – and what they are paid for it – are matters for public auditors.

As long as money is tight – which may now be a permanent condition, compounded in the UK and across the European Union by the health and social care pressures of ageing – public and parliaments have no choice but to demand more value for money. Short of an administrative revolution in which general managers themselves suddenly acquire new financial competence, they are increasingly going to find auditors colonising their terrain.

David Walker is contributing editor to the Guardian Public Leaders Network

• Want your say? Email us at public.leaders@theguardian.com.

Join the Public Leaders Network for more comment, analysis and job opportunities, direct to your inbox. Follow us on twitter via @Guardianpublic.