Pocklington Ward Councillor Andy Strangeway has officially left the Independent group based at County Hall, Beverley.
The move comes after Mr Strangeway declined to go to an Independent group meeting to discuss letters received from the chief executive and the deputy leader of East Riding of Yorkshire Council.
A letter from the group about the meeting said: “We would like to express serious concerns appertaining to your blog and how this may impact upon the reputation of your fellow group members.
“Our particular concern relates to your negative comments, made in the public domain, about officers of this authority, where they have no means of redress.
“The group expects its members to show respect for all employees of this council.”
In a statement Mr Strangeway said: “No independent group can whip an independent as to do so the group becomes a political party and members then cease to be independent. As an Independent councillor, I do not have to take any advice.
“It is my public duty to be willing to challenge poor behaviour wherever it occurs – and this includes the conduct of ERYC Officers.
“My commitment is to Pocklington provincial residents, the law of the land, and the Nolan Principles.”