The campaign spending one-upmanship continues. It's Rep. Jefferson Smith's turn.

More than a month after mayoral candidate Charlie Hales unilaterally announced a campaign contribution limit of $500 $600 and no out-of-state donors, Smith has responded with his own—entirely different—spending cap.

Smith's cap limits individual contributions to $1,000 and has no out-of-state rule. But Smith promises not to take any corporate donations.

Smith also pledges to cap overall campaign spending at $500,000—unless Hales or an independent Hales backer spends more.

"We're going to spend less than Hales. Period," says Smith spokesman Geoff Sugerman. "At the same time, if we end up getting a million-dollar spend against us, we're going to respond to that."

The most unusual part of Smith's pledge is a promise to report all campaign contributions within three days. State law gives a 30-day window to report, and campaigns typically use that to hide big donations in the final weeks leading up to an election.