Call it church-state espionage.

Unitarians and other activists on the religious left have been slipping into evangelical pews to endure altar calls, praise songs and sermons against gay marriage. The Kansas-based Mainstream Coalition has a simple reason for doing this. If preachers openly endorse President Bush, its agents can report these crimes to the IRS.

Reacting to these watchdogs on the left, the Religious Freedom Action Coalition promptly launched Big Brother Church Watch -- www.ratoutachurch.org -- to infiltrate churches that might back Sen. John Kerry. Big Brother agents will, for starters, target Unitarian Universalists, the African Methodist Episcopal Church and the predominantly gay Metropolitan Community Church.

The good news is that this strategy may increase church attendance, quipped the Rev. James L. Evans of the First Baptist Church in Auburn, Ala.

"Reports from both groups seem to indicate that the monitors will be going out two by two," said Evans, in a satirical essay for the University of Chicago's Martin Marty Center. "Monitoring pairs could easily become monitoring teams. We could witness the rise of monitoring communities.