Tax deal with Switzerland attacked by MPs for favouring dodgers over Britons who pay full dues

A deal with Switzerland aimed at clamping down on people using its secretive banks to avoid tax has come under fire from MPs for giving dodgers 'more favourable tax treatment'.

As well as getting better treatment than people who paid up in full, tax evaders had been allowed time to move their assets elsewhere, the Commons Treasury sub-committee complained.

Its report on efforts to tackle tax avoidance and evasion also concluded voluntary compliance should be encouraged by demonstrating that tax authority HMRC 'treats all taxpayers fairly, whether they are individuals, small businesses, or large corporations'.

Tax clampdown: Deal with Switzerland was welcomed by Chancellor George Osborne last year

The Treasury committee report follows a barrage of complaints about the way HMRC handles the tax affairs of huge corporations - including allegedly cosy deals involving Vodafone and Goldman Sachs - compared with the way it deals with small firms and ordinary taxpayers.

Its findings today repeated criticisms made by other influential House of Commons committees over the handling of negotiations with major businesses over their tax arrangements.

While there was evidence the system was actually working well, high-profile cases had produced a public perception that big firms got preferential treatment, it contended.

The deal with Switzerland was welcomed by Chancellor George Osborne last year as forecast to generate up to £5billion for the Treasury and to end the days when it was easy to 'stash the profits of tax evasion' in the country's banks.

In their report, Treasury committee MPs acknowledged it 'may turn out to be a step forward in reducing opportunities for individuals to avoid tax', but they were critical because levies on assets were set slightly lower than the 50 per cent top income tax rate in the UK.

HMRC said the lower rate reflected the fact that the money would be received by it earlier in the financial year than it received the state's take of salaries - but the Treasury committee warned that it could dissuade others from complying.

The report said: 'We do not see why those with offshore bank accounts, who may not currently be fulfilling their tax obligations, should be treated any differently.

'Any perception that those with offshore accounts are paying lower taxes than compliant taxpayers creates a risk that the agreement may encourage taxpayers to seek opportunities to evade tax in the belief that they will be able to reach a favourable settlement in future.

'Also, any perception that some taxpayers are receiving more favourable treatment than others is likely to discourage voluntary compliance.'

It also raised fears that the new rules would not apply until 2013.