The man was arrested after a tip from the concerned family of the disabled woman led police to the man's vehicle, which he'd parked on a deserted forest road outside in Hudiksvall in northern Sweden in January of this year.
When they entered the van, police caught the man in the act.
The politician, whose day job was as a disabled transportation driver, drove the woman every day and had long been suspected by the woman's family.
It was subsequently revealed that the man had had sex with the disabled woman on a number of occasions between September and December last year.
During his trial, the man claimed that he and the woman were in a romantic relationship, but the court didn't buy the man's explanation.
He was found guilty and sentenced to 18 months in prison.
"The woman is dependent on being transported between her home and her daily activities and was in a dependent position vis-a-vis the driver," the Hudiksvall District Court wrote in its ruling, according to the Aftonbladet newspaper.
Despite the conviction, the man can continue to work as a politician, according to the local party chair.
"We don't have any legal way to remove him from the political assignment he has, but are going to try to get him to resign himself," the party official told Aftonbladet.
In addition to being sentenced to prison, the man was also ordered to pay 85,000 kronor ($12,100) in compensation to the disabled woman.