A change in Germany's capital gains tax has prompted an exodus from its churches as thousands of registered members quit their parishes rather than pay the money.

Dioceses have reported in recent weeks that the number of members deserting them has jumped compared to last year as banks prepare to withdraw church tax at source for capital gains from January 1st next.

German tax authorities collect an 8 or 9% premium on churchgoers' annual tax bills and channel it to the faiths to pay clergy salaries, charity services and other expenses.

Members must officially leave the church to avoid paying this.

Under a simplified procedure starting next year, banks will withhold that premium from church members earning more than €801 in capital gains annually and pass it on to tax authorities for distribution to the churches.

Letters from banks announcing the new procedure, and asking clients for their religious affiliation, have worried many members.

Churches have scrambled to explain the changes.

National statistics are not yet available, but individual cases reported in recent weeks illustrate the problem.

For example, both the Lutheran diocese in Berlin and Stuttgart's Catholic diocese reported a 50% jump in departures in the first half of 2014. 

That means about as many quit in only six months as had left in a full year before.

Some clergy have accused financial advisers of telling clients to quit their churches if they don't want to pay up, a step that would have them barred from receiving the sacraments, being married in church or having a religious burial.

The church tax system assures large annual sums for the churches but the steady stream of departing members and declining religious practice are slowly eroding its base.

Catholics and Protestants each make up about one-third of Germany's 80-million population.