“SHADOW companies” and spivs are sneaking nearly £50 billion pounds of owed tax past our cuts-crazed Chancellor each year, a tax expert claimed yesterday.

Trade unions and campaigners against austerity have demanded a crackdown at Companies House after the Tax Justice Network’s latest calculations of tax evasion suggested that “rampant fraud” is costing us an amount equal to the government’s spending on housing, the environment and transport put together.

The study draws on HM Revenue & Customs (HMRC) and European Union figures on missing VAT payments to suggest that up to £100bn worth of sales in Britain take place under the table each year.

Unlike bad debts or exploiting legal loopholes — known as tax avoidance — evasion is an outright illegal attempt to withhold payment by not declaring income.

HMRC’s official estimates put tax evasion’s contribution to the “tax gap” at just £10.5bn a year.

But report author and tax expert Richard Murphy has accused tax chiefs of cooking the books, saying the EU and HMRC’s own figures state that 9.7 per cent of VAT is never paid.

That in turn suggests unrecorded sales of £100bn in 2011-12 alone — and businesses which ducked their VAT obligations are unlikely to have paid national insurance, income tax or corporation tax on those earnings either.

Yet watchdogs rarely check whether a company was still trading or not — about 400,000 companies a year fail to file their annual returns with Companies House.

And HMRC investigated just 470 small businesses’ tax returns in 2011-12 — one firm for every 5,700. Budget cuts have forced the tax agency to axe 30,000 jobs since 2008.

In all, the Tax Justice Network projects that evasion will account for £47bn of Britain’s tax hole this year.

Network director John Christensen said the tax gap was simply “about political will.

“What we have is a government so intent on cutting what it considers red tape that we have ended up with rampant fraud in the UK.

“That imposes a cost on all of us, whether through higher tax bills for honest taxpayers or by cuts in services that many depend upon to make their lives possible,” he said.

Public-sector union PCS, which represents HMRC workers, slammed Con-Dem budget cuts in light of the findings.

PCS has thrown its weight behind the People’s Assembly demonstrations on June 21.

“Collecting even a fraction of this money, squirrelled away by the very wealthy, would change the debate about public spending overnight,” a PCS spokesman said.

“It is clear that HMRC needs to stop cutting jobs and start investing properly in staff and resources to enable it to fulfil its important role, which is central to all the other public services that we all rely on.”

UK Uncut’s Molly Solomons said: “With over half a million people in the UK using food banks the public purse needs every penny and it’s clear the government aren’t serious about clamping down on tax avoidance and evasion.

“The government have been justifying savage cuts by saying Britain is broke, but it’s clearly not,” she said.

The Chancellor’s office did not respond to requests for comment.