Sen. Olympia Snowe (R-Maine) indicated Monday that she would give Senate Democrats the votes they need to block passage of the 2005 budget resolution if it comes back from a House-Senate conference without stringent restraints on spending.

“From my standpoint, it wouldn’t be likely that I would support it” without a Senate-adopted amendment instituting pay-as-you-go rules for both new spending and tax cuts, Snowe said.

The rule would require 60 votes to approve any new deficit spending not included in the budget resolution. The House did not include similar language, though a separate bill moving in the chamber would apply PAYGO rules only to new spending, not to tax cuts.

“PAYGO needs to treat spending and tax cuts equally. That’s the message I would send to the conferees,” Snowe said. “It would place me in a very difficult position if it comes back without it.”

Snowe said she did not want to take a more forceful stance because she did not want to be seen as “issuing ultimatums.”

“I’d prefer to have a discussion with the leader first,” she said of needing to explain her position to Senate Majority Leader Bill Frist (R-Tenn.)

If Snowe stands her ground, Democrats — all but one of whom opposed the GOP-drafted budget — appear to have enough votes to block the budget blueprint from governing Congressional spending.

Sens. John McCain (R-Ariz.) and Lincoln Chafee (R-R.I.) have already said they would not vote for the measure unless it includes the spending restraints passed narrowly by the Senate.

The loss of those two Republicans plus Snowe would give GOP leaders a maximum of 49 votes — one short of the number they need to have Vice President Cheney break a 50-50 tie.

But a senior Senate GOP aide said Republicans hope to convince a few Democratic moderates to break ranks.

Snowe, meanwhile, appeared skeptical of a proposal floated by GOP budget writers in both chambers Monday. The proposed compromise on PAYGO would allow the Senate to keep the rules it adopted, while leaving the House without any such restraints.

“You have to have something that’s solid,” she said. “It’s hard to anticipate how they would craft that. … We have to treat these issues very seriously if we’re going to impose some means of fiscal discipline.”

Still, Snowe noted that she supported a budget resolution last year that included different tax-cut numbers for the House and Senate.