ARB board member and RIBA councillor Yasmin Shariff has called on the institute to stop interfering in the work of the registration body.
Shariff has demanded that rebel board member Ian Salisbury - and his 'unnamed backers in the RIBA' - rein in their campaign to abolish the ARB and work towards constructive reform.
She told the AJ that 'the RIBA must fork out for legal advice' on the role and size of the board and cease 'this underhand and unproductive campaign'.
'Neither the RIBA or the ARB is being helpful, bickering like divorcing parents and, as in all these situations, it is the children that get hurt. The children here are normal practising architects.
'Ian Salisbury has done a good job bringing the board's role to light, but he should now step back and allow sensible negotiations to go ahead, ' Shariff added.