Savers will go back to storing cash under the mattress if the taxman wins the power to seize money from bank accounts, experts warned last night.

They said HMRC’s record of blunders meant it could not be trusted as ‘judge, jury and executioner’ over people’s money.

Officials want to be able to take funds directly from the current accounts, joint accounts or ISAs of those owing it money.

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Under new debt recovery powers, officials want to be able to take money directly from the current accounts, joint accounts or ISAs of those who owe money to HMRC

But this ‘could lead to customers thinking their money is not safe and cashing out their savings, leading to a return to cash under the mattress’, says the Building Societies Association.

The Institute of Chartered Accountants said HMRC would inevitably make errors that could have damaging consequences.

The Law Society, the Federation of Small Businesses and human rights group Liberty have written jointly to the Chancellor urging him to abandon the plans.

Around 17,000 people a year would have money seized under the debt recovery powers, all without the need for HMRC to go to court.

Official documents reveal it expects to receive £375million from the scheme between 2015 and 2019.

It says it will ensure its targets always have at least £5,000 left over after any raid on their accounts.

But it is feared worried savers might opt to keep their cash at home, exposing themselves to theft.

They would miss out on interest on their money and, in extreme cases, simply forget where they left it.

Previous articles: The Mail from May 9, pictured left, and The Mail from May 17, pictured right

It is also likely that tax dodgers – who are the real target for HMRC – might move their money offshore.

In its response to a consultation on the scheme, the Institute of Chartered Accountants in England and Wales said the rules would be side-stepped by the unscrupulous and any mistakes would erode public trust.

It warned: ‘Those who intend to avoid paying tax can – once they know that direct recovery of debts is an option – easily side-step it by taking their funds out of their UK bank accounts.

‘HMRC does not explain how it would counteract this simple and obvious strategy.

But experts say HMRC, pictured above, cannot be 'judge, jury and executioner’ over people’s money

‘Introducing the direct recovery of debts could in fact encourage such people to move their funds offshore.

‘The publicity given to any case where the direct recovery of debts is used inappropriately would have a damaging effect on public confidence in the tax system.

‘In the UK, voluntary compliance and trust in the tax system are crucial to the way the system operates.

‘The cost of trust being eroded will far outweigh the sums the direct recovery of debts is expected to yield.’

An online petition on the Government’s website calling for the proposals to be withdrawn has attracted more than 1,800 signatures.

Patrick Stevens of the Chartered Institute of Taxation said it was a ‘dangerously bad idea’.

‘HMRC has been known to make mistakes,’ he added.

Pressure groups have urged George Osborne to abandon plans which allow HMRC to take funds straight from the accounts of those owing money

‘The people who are most likely to be hit by this are vulnerable people who are not able to deal with HMRC so well. Other people who are not so vulnerable will just make sure that they do not have enough money in bank accounts that HMRC can get their hands on.

‘We honestly do think it is a bad idea. We are not accusing them of making mistakes all the time – but this is just dangerous.’

In May, David Gauke, the Exchequer Secretary to the Treasury, said he recognised there were ‘concerns about the impact of this change on vulnerable members of society’.

But he added: ‘We must ensure that there are strong safeguards in place so that this is only targeted at the truly non-compliant.’

Anybody who has money removed from their account will have been contacted a minimum of four times before it is seized.

An HMRC spokesman said: ‘A very small number of the country’s many millions of taxpayers refuse to pay what they owe despite being well able to.

‘This is simply unfair to the vast majority.

‘The Direct Recovery of Debt proposals contain numerous safeguards – the average debt is £5,800 and most of the 17,000 taxpayers potentially affected have around £20,000 in cash available to them.