The former board member has claimed that a controversial new policy to be debated at a board meeting this Thursday could lead to a hike of 10 per cent in the cost of being on the register.
Salisbury said that if board members vote to back the idea of compulsory CPD certification for all registrants, then many would chose to resign instead.
He claimed that around 10 per cent of those on the register are retired and continue to pay their retention fee 'for old times sake' and would rather drop off the list than do the work required to stay on it.
This, he said, would lead to a sudden slide in the ARB's finances, triggering the retention fee increase.
However, Salisbury also said the entire CPD strategy was flawed due to its impact on the profession.
'There should have been more work done on assessing the impact that this new policy will have.
'And the RIBA also missed a trick; it should have stood up and said that this is for us, not you,' he added. 'But it didn't.'