WASHINGTON — The House voted Thursday to let the Bush administration move ahead with proposed rules that could stop at least 644,000 white-collar workers from receiving overtime pay, heeding a White House veto threat and taking the side of business in its battle against unions.

Lawmakers voted 213-210 to reject a Democratic provision that would have derailed the regulations. Unless a law is passed preventing it, the proposed rules will take effect, perhaps as early as the end of this year.

Senate Democrats had been planning a similar effort to block the regulations. But with the outcome in the House vote, a Senate attempt would seem to be little more than a political statement.

The House vote was a victory for President Bush and Congress' Republican leaders. With the ranks of jobless Americans growing, Democrats are hoping to use Bush's stewardship of the still-weak economy in next year's presidential and congressional elections by arguing that the GOP has inadequately protected workers.

"Today's action is a victory for workers and employers alike," Labor Secretary Elaine Chao said in a statement, thanking supporters for a "very courageous and principled vote."

Three Democrats joined 210 Republicans in opposing the provision. Voting for it were 195 Democrats, 14 Republicans and 1 independent.

AFL-CIO President John Sweeney said the administration effort showed "a callous disregard for the millions of workers who depend on that extra income to make ends meet."

The proposed rules would require overtime — pay equal to 1 1/2 times the hourly rate — for as many as 1.3 million additional low-income workers when they work more than 40 hours per week, the department said. Democrats did not oppose that expansion of the number of workers who would get the extra money.

Democrats and unions say at least 8 million white-collar workers now required to get overtime would lose it due to new definitions of jobs that would be exempt from the extra pay. The Labor Department says the figure is at least 644,000.