The vote was 54-45, and left the fate of the controversial new regulations uncertain. The House blessed the administration's proposed rule earlier this year, and congressional negotiators will have to untangle the disagreement.
Sen. Tom Harkin, D-Iowa, who led the effort to overturn the proposed rules, said the Department of Labor had acted in a "very heavy-handed manner" in crafting a proposal that would "wipe away the overtime protections" enjoyed by millions.
But Sen. Judd Gregg, R-N.H., said the vote was premature — that the Labor Department hadn't yet finished drafting the new rule — and the claims by labor and its allies were wildly inflated. The number of workers who would be cut off from overtime eligibility is more like 800,000, he said. But Gregg noted that a different part of the proposal would have extended overtime pay to 1.3 million workers not currently eligible.
The issue was heavily lobbied on both sides, and in a rarity, all four of the Democratic presidential contenders arranged their schedules to be present. All voted to block the regulations.
The voting was largely along party lines, although six Republicans voted to block the Labor Department from proceeding and one Democrat, Sen. Zell Miller of Georgia, sided with the administration.
The proposed rules — which would not affect workers under union contracts — will take affect as soon as early 2004 unless a law is enacted blocking them.
Standing in Democrats' way is the Republican-led House, which in July voted to uphold the rules by 213-210 after the chamber's GOP leaders switched several votes at the last moment.
The new rules would also make overtime available to 1.3 million additional low-income Americans, the administration says, by raising the annual pay below which overtime must be paid to $22,100. That figure is currently $8,060, where it was set in 1975.
The Democratic amendment would not rescind that part of the proposed rules.
According to the Labor Department's latest figures, 11.6 million workers earned overtime pay in 2000.
Democrats offered the provision blocking the overtime rules as an amendment to a $137.6 billion measure for next year's labor, education and health programs.
House-Senate bargainers will spend the next few weeks writing a compromise version of that underlying bill, under pressure from GOP leaders and the White House to omit language derailing the overtime plan.