Fresh questions have been raised over the legal ambitions of the big four accountants after Deloitte and Pricewaterhouse-Coopers (PwC) in recent weeks split from some of their most respected legal allies in the face of mounting regulatory pressure.

Most dramatically, Deloitte last month confirmed that it is to cut all links with its largest tied law firm, the 340-lawyer Deloitte & Touche Juridique et Fiscal.