A West Norfolk councillor has become the fourth member of the authority’s ruling Tory group to defect in the past year.
Stephanie Smeaton, who represents the Heacham ward, resigned on Friday and will now sit as a member of the Independent Alliance group.
She said she had had concerns about whether she should remain in the Conservative grouping for several weeks.
She added: “I feel the people of this borough deserve better. We have now got to the point where we’re only rubber-stamping cabinet decisions.”
Council leader Nick Daubney said he was disappointed by Mrs Smeaton’s decision, but defended his administration, which he said had made the council one of the most efficient in the country.
He said: “I’ve been very clear with my group about the direction this council is going in if they elect me as leader.”
However, Alliance leader Paul Foster, who was the first to leave the Tory group last year, said: “I’m delighted she has come across.”