The Association of Revenue and Customs (ARC), the union representing senior staff at HMRC, is calling for the government to make additional resources available to tackle tax avoidance.

ARC said it welcomed the recent Public Accounts Committee (PAC) report, Tax Avoidance: Tackling Marketed Avoidance Schemes and endorsed its comments on the need for an advance rulings system and a policy of 'naming and shaming'.

However, the union said it was 'disappointed' that the PAC report did not mention additional funding for HMRC to pursue these activities, other than the £77m announced in last year's autumn statement.

ARC president, Gareth Hills said: 'ARC published its interim investment proposals in December last year to help reduce the deficit and close the tax gap, and showed how an even relatively small scale investment of £120m would recoup currently lost tax of £3.7bn.'

'The scale of the overall budget deficit of £126bn, and the tax gap of £32bn, are such that the government needs to put significant investment into HMRC. By investing in key personnel in HMRC the government will be guaranteed a significant return. Now is the time for it to abandon caution, the time for it to be bold, and the time for it to back a cast-iron winner,' Hill said.