WASHINGTON --

The Senate on Tuesday gave preliminary approval to a bill that would give police officers, firefighters and other first responders the right to unionize but take away their ability to go on strike.

The 69-29 procedural vote proved the measure would survive any possible filibuster attempt. The Senate will vote to send the legislation to President Bush later this week.

The bill would guarantee public safety officers the right to join unions and bargain over wages, hours and conditions of employment. It also would ban them from going on strike.

Two states, Virginia and North Carolina, prohibit public safety officers from collective bargaining. At least 20 other states don't fully protect collective bargaining rights for firefighters, police officers, corrections officers and emergency medical service workers, supporters said.

States could exempt towns with fewer than 5,000 people or fewer than 25 full time employees.

"Fairness means fire fighters and police officers having a voice at the table in life-and-death discussions about their work," said Sen. Edward Kennedy, D-Mass., chairman of the Senate Health, Education, Labor and Pensions committee. "They know best how to do their jobs effectively, efficiently and safely. Everyone benefits when they're given the chance to share that knowledge at the bargaining table."

Republicans called the bill payback for union help in elections.

"While American families are facing an uncertain economy, Democrats are shamefully pushing another job-killing bill to help line the pockets of organized labor," said Sen. Jim DeMint, R-S.C. "Let's be honest: This bill is a political payoff to big labor bosses, whose political support is needed to keep Democrats in charge of Congress."

Democratic Sens. Barack Obama of Illinois and Hillary Rodham Clinton of New York, interrupting their presidential campaigns, voted to begin debate on the bill. Sen. John McCain, the presumptive GOP presidential nominee, was not present.

The bill "makes sure those on the front lines, who make snap decisions in saving lives every day, have a voice in protecting themselves and their communities," said Harold A. Schaitberger, president of the International Association of Fire Fighters.

Three of Bush's Cabinet secretaries, Labor Secretary Elaine Chao, Attorney General Michael Mukasey and Homeland Security Secretary Michael Chertoff say they will recommend that Bush veto the bill.

"It represents an unprecendented federal intrusion into state and local decision making, potentially disrupts our nation's carefully developed emergency response functions and raises serious constitutional questions under the Tenth Amendment," they said in a letter to Senate leaders.

The White House said Tuesday that it opposed the bill.

"The administration strongly opposes this Act because its severe intrusions on state sovereignty and emergency management conflict with the fundamental principles of federalism," an administration statement said. "If H.R. 980 were presented to the President, his senior advisers would recommend that he veto the bill."

But Chuck Canterbury, president of the Fraternal Order of Police, said President Bush has assured the FOP that he will sign the bill. "On three separate occasions, the president has personally assured us he would sign this bill if it reached his desk. I will ask him to reject the advice of his advisers and sign the bill," he said.

The bill passed the House in July on a 314-97 vote, which along with the Senate vote, would be enough to override a presidential veto.