Three Republican senators unveiled a campaign finance bill yesterday that would prohibit political action committee contributions in Senate races and curb the advantage of millionaire candidates.

Sens. Mitch McConnell (Ky.), Bob Packwood (Ore.) and John McCain (Ariz.) outlined the bill at a news conference and offered it as an alternative to a more sweeping Democratic proposal approved by the Senate Rules Committee.

The bill would ban PAC contributions to candidates, but not political parties, and raise the ceiling on contributions from $1,000 to $10,000 for candidates who run against an opponent who spends more than $250,000 of his own money on the campaign.

The legislation also would require groups, such as organized labor, to report to the Federal Election Commission money spent on behalf of a candidate or for registration and get-out-the-vote drives.

The bill approved by the committee would provide for a voluntary system of taxpayer financing of Senate elections, and would limit spending and PAC contributions.

At their news conference, Packwood and McConnell said the Democratic bill would run into a filibuster that could not be broken.

"There are already ample enough votes to sustain a filibuster," Packwood said, adding that he hoped the Democrats would "negotiate and come up with a compromise" that could attract overwhelming backing.

The Republicans said the principal objection to the Democratic bill is the portion that provides for taxpayer financing of Senate elections, similar to the one in effect for presidential elections.

McConnell said, "Having tripled the national debt during the last 10 years, the last thing the Congress should do is create another federal entitlement program to fund our reelection campaign."

Packwood added that adopting the Democratic proposal would be "to tap the till of the taxpayer to finance our campaigns" and put the "government in the driver's seat, the PACs right next to it, while the individual rides in the rumble seat -- if at all."