Bipartisan group to attach surplus `trigger' to Bush budget.(Knight Ridder Newspapers)

WASHINGTON _ Worried that predicted federal budget surpluses might never appear, a group of senators will propose next week that any new tax cuts include a "trigger" mechanism.

The device would allow each new phase of a tax cut to go into effect only if surpluses continue to pile up annually, permitting the government to keep paying down the national debt.

This idea could make President Bush's sweeping $1.6 trillion, 10-year tax cut plan more appealing to skittish Americans _ and to analysts who warn that it could drag the government back into deficits or painful budget cuts if the surpluses don't materialize.

But Bush rejects the notion, saying it would drive Democrats to push up spending to crowd out the tax cuts they oppose. And veterans of Washington budget negotiations from both major parties warn that the trigger is nothing but a feel-good gimmick that won't work. They cite recent history to buttress their point.

Nevertheless, a small bipartisan group of centrist senators led by Evan Bayh, D-Ind., and Olympia Snowe, R-Maine, insists that Congress needs to do something to safeguard against financial disaster. They warn that there is no way the government can know for certain that it will continue to amass ever larger budget surpluses, totaling $5.6 trillion over 10 years.

"Most economists say they can predict economic growth with near certainty for the next six months, and they feel comfortable predicting as far as two or three years down the road," said Sen. Mary Landrieu, D-La. "However, a majority of the proposed $1.6 trillion tax cut being discussed does not kick in for at least five years."

The nation's most influential economist, Federal Reserve Chairman Alan Greenspan, is among those who endorse harnessing tax cuts to a trigger. He also supports tying spending increases to a similar procedure, though no one in Congress is proposing that.