The Big Four may be behaving in a predatory manner to drive off the challenge from the mid-tier, the managing partner of BDO Stoy Hayward has suggested in some of the most explosive comments yet on the UK dominance of the Big Four.

BDO Stoy Hayward’s Jeremy Newman said that his firm had been beaten to a due diligence contract recently after a Big Four firm slashed its fees to a third of its original pitch to win the work.

The suggestions will raise further questions about the dominance of the Big Four, who have pulled away from their mid-tier rivals in revenue terms, figures compiled for Accountancy Age are set to show.

Jeremy Newman detailed on his blog how a Big Four firm had brought their fee down to £220,000 after originally pitching at more than £600,000. BDO had made an initial pitch capping its potential fee at £200,000 and eventually lost the contract.

According to Newman, the company – a UK subsidiary of a continental group – was told to discuss the fees position further with the Big Four firm, who agreed to reduce their fees. ‘Maybe, just maybe, this is “unfair” competition.’

‘Maybe, just maybe, this is “predatory” pricing designed to force us out of competing in this sector of the market place,’ ha said.

The Big Four are highly sensitive to charges that the market for UK accountancy services, and audit in particular, is uncompetitive. The Oxera review concluded there was no lack of competition and the term was dropped from the FRC review, which is now only into ‘audit choice’.

Newman said he would not refer the incident to the Competition Commission, but had published the details to stimulate debate.

A spokesman for the commission said this week: ‘The Competition Commission is well aware of concerns with regard to the Big Four but price discrimination can in different circumstances be seen as both pro and anti competitive.’

None of the Big Four commented as Accountancy Age went to press.