The leader of Northamptonshire County Council said she is consulting her lawyers over a tweet that she believes overstepped the mark in criticising her role in the financial mess at County Hall.
Councillor Heather Smith said a comment by recently-elected councillor Jason Smithers when the pair were engaged in a Twitter back-and-forth was a step too far.
Councillor Smith said: "I'm not putting up with all this outrageous stuff he's doing. I'm taking legal advice.
"He's just throwing all these comments out there in public so people can view them.
"They're libellous. I've had enough," she said.
The online spat came in the aftermath of Tuesday's cabinet meeting where senior members that drew up the most destructive budget the county has seen for years endured barbs and criticism.