A council chief executive has promised she will take legal action against three councillors if they do not "improve their behaviour".
Rutland County Council has voted to back several officers against UKIP councillors Richard Gale, David Richardson and Nicholas Wainwright.
They are alleged to have made defamatory statements on a website and harassed staff in a series of emails.
The three men have not responded to requests to speak to the BBC.
But they told the Stamford Mercury they had taken legal advice which said they had no case to defend.
Chief Executive Helen Briggs said she would not let the councillors "disrupt" the council.
The three men previously went under the name the Rutland Anti-Corruption Group, but became the first UKIP councillors in the county when they joined the party in June.
The council has agreed to fund any legal action taken by its officers against the trio after lawyers suggested they had a strong case for defamation.
An apology and retraction was demanded from the group which, the council said, had yet to be received.
Speaking at a full council meeting this week, Ms Briggs said: "I will not allow these three councillors, or anyone else for that matter, to continue to disrupt the effective operation of this council, and me as its chief executive.
"You have given me a clear mandate to bring proceedings for defamation in my own name.
"Before doing so, I intend to allow these three councillors a short period of time to show whether they can moderate their recent behaviour, and operate as councillors would be expected to, but I shall not hesitate in commencing proceedings unless there is a marked improvement in their behaviour."