Democrats are preparing to take Senate Minority Leader Robert J. Dole (R-Kan.) at his word now that he is telling presidential campaign audiences that he wants to overhaul the rules for financing senatorial campaigns.

"He says he wants to negotiate a bill. Okay, we'll negotiate a bill," a Democratic strategist said. "If he wants to get this thing off his neck, if he wants people to stop following him around with placards asking him where he stands, he can do it now."

Democrats are not just being accommodating to the leader of the opposition in his race for the Republican presidential nomination as they prepare to fight again next week over campaign-spending limits.

As Democrats see it, Dole was the pivotal force behind a Republican filibuster that blocked action on a spending-limit bill last year, despite a record-breaking series of seven cloture attempts by Majority Leader Robert C. Byrd (D-W.Va.) and Sen. David L. Boren (D-Okla.), chief sponsors of the measure.

In its current form, modified twice to gather support, the Byrd-Boren bill would provide incentives for a candidate to accept voluntary spending limits in primary and general election campaigns. Mandatory limits have been ruled out by the Supreme Court. Candidates who adhere to the limits would get reduced postal and broadcast advertising rates and be eligible for public financing to offset any spending by an opponent that exceeds the ceilings. The bill also puts an aggregate ceiling on the amount a candidate could receive from political action committees (PACs).

Republicans, including Dole, reject the idea of any spending limits or public financing and have rallied around a Dole-sponsored alternative that would put tighter limits on individual PAC contributions and require more disclosure of campaign-financing information.

Dole and other Republicans contend that spending limits amount to a "Democratic incumbents' protection act" because they would block GOP spending to overcome party registration and other advantages of entrenched Democrats in regions such as the South. Democrats argue that Republicans have a fund-raising advantage and won't give it up. Common Cause, the lobbying group spearheading support for the Democratic bill, adds that Republican senatorial candidates won in the South in 1980 with spending below the proposed limits, adjusted for inflation, but lost seats there in 1986 when they spent beyond the limits.

What frustrates the Democrats is that Dole claims to be working hard on a solution, playing down his role in the filibuster when he is confronted by questions and placards inspired by Common Cause. "It takes 40 people to carry out a filibuster, and I'm only one," he has said.

If a deal is in the works, Democrats contend, they have yet to see Dole's opening bid. One Democratic strategist said last week that if Dole refuses to negotiate, Byrd and Boren may start meeting with Republican moderates who are sympathetic to campaign-financing changes in hopes of breaking the filibuster by attrition.

Byrd has once again given the Democratic bill top priority, hoping to capitalize on election-year concern over the soaring costs of campaigns and money's influence on governmental decision-making. He and Boren plan to resurrect the bill next week and make another stab at breaking the GOP filibuster that is virtually certain to be resumed.

But they are still at least five votes shy of the 60 needed to impose cloture and limit debate. They have some hope, but no certainty, of picking up the last two Democratic holdouts as well as some moderate Republicans who have indicated support for some kind of campaign-spending limits.

The problem is that any substantial GOP support may be difficult if not impossible to get as long as Republicans, responding to pressure from Dole, refuse to negotiate a compromise that includes spending limits and public funding to encourage acceptance of the limits. And Democrats, ranging from Byrd through more liberal elements of the party, want any campaign-financing bill to result in spending limits.

"The key," said a Democratic aide involved in the maneuvering, "is getting some movement from Bob Dole."

This is what Democrats have in mind for next week when the Senate returns from a week-long recess and Dole winds up his New Hampshire primary campaign. "He knows he's going to get called on it . . . . He's going to get asked to put up or shut up," said a Democrat. An aide said Dole has a speech prepared in response.