South Taranaki deputy mayor Alex Ballantyne has been voted out of the job at a council meeting held behind closed doors in Hawera today.
Mr Ballantyne has been a vocal supporter of Eltham residents affected by the foul odours caused by Fonterra dumping three million litres of buttermilk at the town's wastewater plant last year.
Councillors voted seven to five to ditch him and appoint a new deputy mayor.
Mr Ballantyne said he had been ostracised since speaking out at a public meeting and was the victim of a serious wrongdoing.
"I've been basically cut adrift, sent to Coventry, and this is brought to a head," he said.
"The mayor has obviously been working through it, got the numbers and formally done what he's done informally for the last year."
But South Taranaki Mayor Ross Dunlop said Mr Ballantyne brought the demotion on himself by making inaccurate and alarmist comments about the situation in Eltham.
Mr Ballantyne has been on council for 16 years and was in his second term as deputy. He will remain a councillor.