Cllr Heather Taylor, a former Lord Mayor of Canterbury, has quit the city council’s Conservative group.
The Sturry councillor has become the third member of the council’s Independent group.
Her decision apparently shocked Cllr Simon Cook, the Conservative leader of Canterbury City Council.
Asked why Cllr Taylor had left the group, he told the Canterbury Journal this afternoon: “Afraid I don’t know – you’d have to ask her.”
But Cllr Neil Baker, the council’s communities chairman, offered an explanation.
He said: “We are lucky to have a number of people who want to stand as Conservative council candidates.
“Unfortunately, this means some will miss out on being selected. We thank Heather for her work for the party over the years and wish her the best.
“Going forward, we have a strong team in place to stand as representatives for all people in the Sturry ward in May next year.
“We followed our rules for selection, laid down by the national party, and the two best candidates have been selected.”
The role of Lord Mayor of Canterbury is essentially ceremonial.
Cllr Taylor is said to have discharged her duties with the support of both her constituents and members of her group.
She was first elected to Canterbury City Council in 2006 and presently sits alongside Cllr Georgina Glover as one of the two Conservative councillors representing Sturry.
Cllr Taylor fulfilled her duties as Lord Mayor with her sister-in-law Linda as her consort.
Her entry on the council’s website reads simply: “I am delighted to have been elected to serve Sturry South.
“I will do my best to ensure that I serve the residents of Sturry and Fordwich for the best.”
Cllr Taylor has been approached for a comment.