The Catholic Church in Auckland has written to electricity company Powershop asking it to remove billboards which the church calls outrageous and highly offensive.
The stretch four-and-half-storey high billboards in central Auckland and Wellington depict Pope Benedict marrying a male couple.
Previous Powershop billboards have used dictators such as Kim Jong Il and Saddam Hussein.
In the letter, Bishop of Auckland Patrick Dunn says he is outraged the company has grouped the Pope with people described by Powershop as rotten demagogues.
He also takes issue with the depiction of the Pope marrying two men.
Powershop says the billboards are meant to be thought-provoking and satirical, and will stay up until the end of the month.