Education spending will be a major battleground when the New Mexico Legislature meets for a special session that Gov. Bill Richardson announced Monday will start Oct. 17.

In anticipation of the budget fight, educators and teachers' unions plan a large rally Friday at the state Capitol.

While some lawmakers say school cuts are unavoidable as state government tries to cover its latest revenue shortfall, Richardson repeated his stance that education funds are off limits.

"After meeting with education leaders, I am more convinced than ever that we must fight against attempts to cut school spending," the governor said in a statement. "The superintendents reiterated their strong opposition to drastic cuts that some legislators have proposed."

Richardson has suggested a 3 percent reduction in spending by every state agency except public schools as part of a belt-tightening plan equaling $444 million for this fiscal year.

The governor and lawmakers also have been looking at canceling previously approved capital-improvement projects to free up money and tapping into the cash balances held by programs and agencies.

But several lawmakers say there's no way to avoid cuts to public schools because the looming deficit is so large. Some have said they expect the budget shortfall will be at least $550 million. Lawmakers will receive an updated revenue forecast next week that will set the deficit reduction target for the session.

Legislators are expected to unveil their own spending plan later this week.

To express opposition to cutting education spending, teachers are organizing a march and rally to the Capitol. Already, they are circulating petitions urging lawmakers to repeal income-tax cuts the state adopted in 2003 for those making $295,000 or more annually. The coalition of groups organizing the event said it has invited documentary filmmaker Michael Moore to attend.

The special session, set to convene at noon Oct. 17, a Saturday, will be limited to budget matters, the governor said.

Several advocacy groups have asked him to reconsider rolling back the tax cuts, but the governor said he and lawmakers have agreed that won't be on the agenda. The Democratic governor considers the income-tax cuts an economic development incentive to attract businesses with higher-paying jobs to New Mexico.

House Speaker Ben Luján, D-Nambé, said in an interview with The Associated Press that taxes won't be part of the agenda of the special session because no proposal could be implemented quickly enough to provide much money to help with this year's deficit. However, he said tax measures may be considered during the Legislature's regularly scheduled 30-day session, which starts in January.

"If revenues continue to be as low as they are and we want to keep our schools open, I think that we have no alternative than to look at revenue enhancements of some kind," Luján said.

Richardson, who earlier said the special session would last just one day, said Monday that "the length of the session will be dependent on how long it takes to reach a consensus on the budget."

Contact Kate Nash at 986-3036 or knash@sfnewmexican.com. Read her blog at www.greenchilechatter.com.