Recovery in the UK's downtrodden construction industry could be hindered under proposed tax changes for the majority of builders, an accountancy organisation has warned. If a proposed crackdown on the Construction Industry Scheme goes ahead, the ICPA (Independent Certified Practising Accountants) has warned that up to 300,000 bricklayers, plumbers, carpenters and plasterers who are working as sub-contractors could effectively lose their status as self-employed to the taxman. The move has been dubbed 'a mockery of the government's claims it is trying to reduce red tape for business' by ICPA chairman Tony Margaritelli. Although the move is an attempt to catch out those who falsely claim to be self-employed to reduce tax liability, the ICPA is calling for the government to realise the underlying implications any new rules would create. The changes, it says, will also impact struggling building firms. 'The vast majority of jobbing builders move from site to site as required. These proposals would effectively mean they become 'employees' of each firm that is using them for the period of their contract with them and are taxed on a PAYE basis,' said Margaritelli. He dubbed the idea as 'ridiculous', as individual sub-contractor builders will generate a mass of P45s, thus adding to the administrative burden of building companies. HM Revenue & Customs has estimated that around £350m per year will be generated by the changes to the system, but the ICPA said the majority of this will stem from additional employers' National Insurance charges that are levied on construction companies.