PwC, KPMG, EY and Deloitte must break up their consultancy and audit businesses into distinct firms to provide greater focus on the "most challenging and objective audits", the competition watchdog has said.
"Defective" company audits could mean millions of savers in pensions funds are "losing out", says the Competition and Markets Authority (CMA) as it launches a probe of the audit sector.
The Treasury select committee is to investigate how low interest rates and quantitative easing have impacted the economy since 2008.