The shake-up in who audits the FTSE 100 companies is having a direct impact on the four largest UK accountancy firms. What is less clear is how the unprecedented change in the audit market has affected the original intention of legislation that has led to this upheaval.

By requiring mandatory audit tenders among the FTSE 350 companies every 10 years, and a compulsory rotation of audit firm every 20 years, regulators hoped that more firms would be able to enter this particular market, creating more choice as well as more competition.