It seems that, if Accountancy Age is correct, CIMA left CCAB because they feel that the fees charged to belong to CCAB were disproportionately high.
"CIMA explained that its members were paying a "hugely disproportionate amount" towards the body. However, CIMA's request to renegotiate the fee structure through an arbitrator was turned down by the other institutes: the ICAEW; ACCA; ICAS; ICAI; and CIPFA.
Given that CCAB appears to have done nothing (that it is proud to tell the world about) since December 2009, CIMA may well have a point about the fees.
What exactly are the members of the five remaining professional bodies paying their fees to CIMA for?