The business model of the big four accounting firms of Deloitte , PwC
, Ernst & Young and KPMG is under attack from the European Commission, the Financial Times reported on Tuesday.

The newspaper said the commission is pushing for tough rules to force the firms to abandon their consultancy businesses and share audit work with smaller rivals.

A draft regulation, which the newspaper said it had seen, aims to restore trust in financial reporting in the wake of the 2008 crisis, and is being backed by Michel Barnier, internal market commissioner.

Under the plans, due to be unveiled in November, companies with balance sheets greater than 1 billion euro would be forced to hire two auditors to conduct a joint-audit of their books, including at least one firm other than the big four.