The ARB has been rocked by the second resignation this year of an elected board member. The sudden departure of Nick Tweddell, a long-term critic of the board's activities, comes just weeks after Ian Salisbury shocked observers by stepping down.
Both members received high levels of support at the last election for the profession's board representatives two years ago.
The news was greeted with concern from RIBA president elect Jack Pringle, who claimed there was 'clearly something wrong'.
In his resignation letter, seen by the AJ, Tweddell claimed the board's current attitudes had left him unable to carry out his duties.
'It has become impossible to deliver and discharge my duties to the board and to the profession, ' the letter says.
'Although assurances have been given since my election that proper attention would be given to accountability and openness, I have found the reality for myself as a board member to be quite the opposite.
'If information is restricted from elected board members, then where is democracy? Where is trust?
'I feel that the ARB is currently in competition against the charter bodies, ' the letter added. 'I cannot continue to support such an organisation, while believing that I am providing a useful and necessary service to the public and my profession.' Pringle said the resignation should be troubling for the board. 'It strikes me that we have elected member after elected member resigning from the board and this is not coincidence, ' he said.
'There is clearly something in the operation of the ARB that elected representatives find so unacceptable that they resign, ' he continued. 'It must be in the board's constitution and we are working to get this reformed.' But ARB registrar and chief executive Robin Vaughan said there was nothing for the board to worry about.
'There is no situation for us to recover from, ' he said. 'All that we do when someone resigns is to invite the next person down on the electoral list to join the board.
'Those members of the board who have considered opinions will stay at the table, ' he added. 'The minority will resign and the majority will stay and continue the sensible debates we have.'