A police and crime commissioner who paid back £2,700 after a row about expenses is demanding a refund from HM Revenue and Customs.
Norfolk PCC Stephen Bett claimed £2,700 for driving 96 miles from his "home office" in Thornham to police HQ. He agreed to pay it back last year.
He has told the BBC he is entitled to the mileage and would "fight until I get HMRC to admit they are wrong".
HMRC said it did not comment on identifiable taxpayers.
Mr Bett, who was elected in 2012 on a salary of £70,000, argues that his publicly-funded job should allow him to class his home as his official base.
He claims he has worked this way for 40 years, as a councillor and former Police Authority chairman, and spends most of his time driving directly to appointments "like the chairman of a company travelling between offices".
He said he drives to the Wymondham headquarters "once every couple of weeks" when necessary.
Mr Bett paid back £2,700 he had claimed in mileage after an independent audit last year.
He was also investigated by City of London Police but faced no criminal charges.
At the time, his monthly mileage claim was about £500. In the current financial year, his claims have amounted to about £150 a month.
Mr Bett said he is continuing to dispute the matter with HMRC two years after the row began.
"No-one wants to make a decision and it seems that my papers are currently lost in the system," he said.
"It's typical of a government department, they are ineffective.
"They keep passing my case around and want to be as obstructive as possible in order to avoid a tribunal hearing."
He added: "My accountant and lawyer say, in law, I am right and I have a right to claim these expenses".
Bernard Rix, an expert on PCC legislation, said he believed Mr Bett was the only PCC seeking to designate his home as his place of work.