A county councillor claims he is ill with worry over £80,000 he could be forced to pay back to the council after it was revealed he was not legally entitled to hold office for the last five years.
Councillor Peter Pinfield, who leads the Labour group on Worcestershire County Council, may face an inquiry by the Standards Board for England after The Birmingham Post revealed he had worked at a "politically restricted" level in Dudley social services for the past five years.
The councillor for Droitwich West, who strenuously denies any conscious wrongdoing, said: "My health has already dramatically suffered.
"I went to see the doctor and he said my blood pressure was up and my diabetes is getting worse.
"This is a very worrying time for me and my family. I am not sure of the exact time I was in the job, or of the amount of money I may have to pay back. I am taking legal advice.
"I will reiterate that neither Dudley Council or myself knew the position I was in was restricted until a week before the election."
Using basic allowances for group leader of £17,000 and figures obtained from Wychavon District Council during the four out of those five years, he was a member there, his income has been calculated at about £80,000.
But some opponents, who are angered the error went unnoticed for so long, have claimed the figure could be closer to £100,000.
Coun Pinfield won back his seat with his biggest majority in the council elections last week, but could still face a legal challenge and almost certainly a by- election because his nomination papers were lodged while he still occupied the restricted position.
He has since asked for and received a demotion with Dudley Council.
He fell foul of legislation brought in in the 1980s to prevent politicians occupying officer roles with other councils which could have political implications.
A few days before the shire elections earlier this month, Worcestershire County Council disqualified him as a councillor but, using its own legal advice, still allowed him to stand.
Former Conservative county councillor June Longmuir, who clashed with Coun Pinfield when she was cabinet member for education, is contacting the Standards Board for England in a move to protect the " integrity of the county council".