Ernst & Young's (E&Y)100-strong regulatory practice has been hit hard by the defection of a team of eight including Trevor Newbery, director of the team.
Newbery is joined by Andy Mills, Stuart Howard, Jonathan Huston and four others in leaving Ernst & Young for Grant Thornton.
Senior sources said that Newbery disagreed with E&Y's move towards larger fees. "E&Y wanted to focus on moving to £1m-plus fees, but Newbery disagreed," said the source.
E&Y confirmed that Newbery and seven others were leaving the company, but refused to comment on any other issues.
Grant Thornton refused to comment.