Government could be wasting over £70m a year because officials are using financial spreadsheets and models which are so complex they cannot be understood properly, according to research by the Fast Standard Organisation.

Fast says opaque financial modelling fuelled inefficiency, a lack of professionalism and costly procurement errors such as the one that plagued the re-tendering of the West Coast mainline franchise. It estimated that the costs to the wider economy are £300m a year.

Fast is a joint industry not-for-profit body which has been launched to promote and maintain the FAST Modelling Standard, a commonly understood language for financial modellers. Backers include Deloitte, Grant Thornton and Mazars.

In its launch report, the group says opaque financial modelling fuels inefficiency, a lack of professionalism and costly procurement errors such as the one that plagued the re-tendering of the West Coast mainline franchise. It puts the costs to the wider economy at £300m a year.

Kenny Whitelaw-Jones, managing director at F1F9 and board member, said: 'No major budgeting decision is government or business is taken without a financial model being created, yet finance professionals have no common spreadsheet modelling language or standards to work from.

'The waste and extra work this creates is costing taxpayers at least £70m a year on our most conservative estimates and the damage to the broader economy is outrageous - certainly reaching hundreds of millions and possibly billions of pounds.'

Fast is urging financial bodies and government to sign up to shared guidelines that are continuously updated and give a 'global language' for building financial models. It says this unified approach could save government money and time, citing the example of Edinburgh council, which has saved £100,000 a year from adopting FAST methods of standardising financial modelling.