Reverend David Boase, 69, is priest at two Episcopal churches in Alton, Illinois.
According to the Washington Post, when he took his US driving test in 2005, a government official asked him if he wanted to register to vote and duly processed his UK documents without raising the issue of citizenship.
Rev Boase admits taking part in a ballot on boosting resources for the local fire department but says he did not know he was doing anything wrong or illegal.
He told the Washington Post: "It's a shame when a person tells the truth and admits fault, intends to explain in all honesty, with full disclosure, and still everything falls apart."
Rev Boase was born in Cumbria and studied at the universities of Durham and Oxford.
He says he feels at home in Illinois and wants to stay there and become a US citizen.
Rev Boase's lawyer believes his case is only happening because of a change to the US Citizenship and Immigration Service brought in by President Trump in an executive order in January 2017.
His local parish have started a GoFundMe campaign to help with his legal fees.
Rev Boase though expects to be deported by an immigration judge on Friday and is currently selling his home and its contents.
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