Washington ? In a sharp rebuke of a new administration policy, the House moved Thursday to block the Labor Department from carrying out overtime rules that critics argued could deprive millions of workers of their overtime pay.

The 223-193 vote in favor of blocking the rules defied the White House. A threatened veto applied to a massive spending bill, now on the House floor, if it contains any language tampering with the rules that took effect Aug. 23.

“This is one step in the legislative process. We are continuing to work with the Congress,” said Trent Duffy, a spokesman for President Bush.

Democrats, united against the rules, were joined by 22 Republicans in voting for the amendment to a $142.5 billion health and education spending bill.

The vote was Bush’s second election-season defeat in Congress in two days. On Wednesday the Senate disregarded a White House veto threat and voted to prohibit Bush from giving federal immigration jobs to private workers.

“The administration has chosen this time to institute new regulations which for the first time in 80 years scale back workers’ entitlement to overtime pay,” said Rep. David Obey, D-Wis., a sponsor of the overtime proposal.

Democrats sought to depict the issue as an election-season example of the Bush administration’s insensitivity to worker rights, saying the overtime privileges of up to 6 million workers were at risk.

“This is the place where making ends meet happens because people have overtime pay. Republicans cannot grasp that,” said House Democratic leader Nancy Pelosi of California.

Democratic presidential candidate John Kerry said the veto threat was “the latest evidence of how dead wrong the Bush administration is when it comes to meeting the needs of America’s struggling middle class.”

The White House and most Republicans insisted the rules would update an antiquated overtime pay system and make an additional 1 million lower-paid workers eligible for overtime.

“I do think that the clarity that comes with these new rules will help better protect American workers,” said Rep. John Boehner, R-Ohio, chairman of the House Education and the Workforce Committee.

It was unclear how much impact the House vote would have on the biggest overhaul of overtime regulations in more than half a century.

The Senate has yet to take up the health and education bill. House GOP Whip Roy Blunt, R-Mo., said he expected that the provision would be removed when the House and Senate meet to work out the final version of the bill.

He said that by that time there would be “overwhelming evidence” that the rules were benefiting tens of thousands of workers.