Mums and Dads using See Saw playgroup at St Philip's Church in Hove say the price to rent the church hall has nearly tripled in the last three years.
According to The Argus rents have gone up from £6000 to £17,000 a year.
Hundreds of people have signed a petition disagreeing the decision, which they claim has forced See Saw to close after 18 years of running at the church.
Parent Angela Whippy told the newspaper: "The Reverend and his committee have pushed the rent up to an unaffordable amount and in effect have closed the pre-school down.
"He is supposed to be running a Christian organisation but his behaviour has not been very Christian."
Revd Stephen Terry, from St Philip's, told The Argus: "Obviously we have to pay our way like everybody else these days and our financial position is very parlous indeed.
"The rate that See Saw was previously paying was heavily subsidised by the church and considerably less than what might be charged to other groups.
"The hall is run by the Parochial Church Council and under charity law, trustees are duty bound to find the best return for the charity that is reasonable.
"We were very sad indeed when See Saw felt they couldn't accept the new rate."