Is George Osborne serious about his budget promise to collect £5bn extra in evaded and avoided tax? That’s a very modest ambition, when the national audit office reports today that £16bn is lost to fraud alone, before you even start on the great company “legal” tax scams. The tax gap – the missing tax not paid – is officially £35bn, but is far more in reality, according to tax experts.

HMRC is criticised for chasing small fry while letting the big fish go, as every fish and chip shop and self-employed tax-payer complains. That’s what happens with absurdly perverse targets: HMRC was told to increase its prosecutions by 1,000 a year, but some of the cases were for as little as £250, and two thirds were for less than £100,000, focusing on income tax, VAT and tobacco duty. Many were small infractions, as when a small business tips over the VAT threshold but fails to register immediately – easy catches. The target should have been for the sum of money raised – in billions. The UK remains a country where penalties are low, and so are the risks of high-rolling tax evasion: HSBC Swiss bank account-holders were treated with discretion and minor fines, while the French and Spanish governments reclaimed more cash, despite fewer evaders.

Stepping up prosecutions aimed to deter others, HMRC estimated £295m would be yielded just by that deterrent effect, but now admit it can find no evidence these 1,000 prosecutions had “led to changes in behaviour or increases in tax revenues”. Heavily publicised big company cases have a greater chilling effect on other companies’ tax scams, whether evasion or avoidance. Excellent that Facebook’s billionaire founder gives 99% to charity – but paying his company tax should come first: avoidance measures meant that Facebook paid just £4,327 in the UK last year, despite gigantic advertising revenue.

Avoidance measures meant that Facebook paid just £4,327 in the UK last year, despite gigantic advertising revenue

Is George Osborne serious? HMRC staff have been cut by a fifth since 2010. Now 137 more tax offices are closing, despite half of the public’s phone calls to helplines going unanswered. DWP staff prosecute 10 times more benefit cheats, worth a fraction of the loss in tax. Britain still protects an archipelago of tax havens and the chancellor has fought tooth and nail against EU efforts to clamp down on tax evasion and avoidance. How extraordinary that four out of 10 government-awarded fracking licences in the UK, including Caudrilla, are held by companies at least partly owned in offshore tax havens, Greenpeace has discovered, as further licenses are announced today.

Tax is falling harder on people, not companies, according to the OECD this month. “Corporate taxpayers continue finding ways to pay less, while individuals end up footing the bill,” said their director for tax policy and administration. “This underlines the urgency of efforts to ensure that corporations pay their fair share.”

But Osborne is accelerating this trend by cutting corporation tax in a race to the bottom between countries.

Tax reliefs are rising, an accretion of 1228 barnacles on the tax code, to the delight of clever accountants: Gordon Brown’s sensible-sounding 2003 research and development relief has mushroomed to £9.5bn, though no one thinks our companies are doing genuine research worth anything like that. Better by far to hand money out as grants for valued research projects, not as tax loopholes. “Entrepreneurs relief” is another fiddle, taxing company directors just 10% in capital gains, losing the Treasury £4.6bn. These are things Osborne would tackle if he were serious.

Meanwhile, the rich get richer. The wealth of the UK’s richest has almost trebled since the crash according to a study of Forbes World Billionaires list.

The high pay centre reports top chief executive pay up by 40% since 2009, to an average of £5m, or 183 times the average salary. They complain they contribute too heftily to the tax take – but you never hear them kick up the fuss they should against the big company avoiders who pay too little.

Next week Margaret Hodge announces her plans for the work of her new all-party committee on responsible tax: expect her to let loose yet more damning research revealing who does and who doesn’t pay their fair share of tax.