COLUMBIA--Opponents of Gov. Mark Sanford's income tax reduction plan, his top legislative priority, were successful Wednesday in fighting off the proposal long enough essentially to kill it.

After three failed attempts in seven hours to seat Democrats filibustering the measure, supporters of the governor's plan gave up and adjourned debate. With four days left in the legislative session and the governor's budget vetoes next up on the Senate calendar, the proposal has little chance of revival.

"We just couldn't get the votes," said Senate President Pro Tem Glenn McConnell, R-Charleston. "Unless we can find three more votes somewhere, the fight is over. And that's a shame because it's an economic development plan that South Carolina needs."

The news reached the governor at the end of a long day. Earlier, the S.C. House of Representative overrode 105 of his 106 budget vetoes.

"We've made it three-fourths of the way through the process," Sanford said. "Unfortunately, that last part is the toughest. We have the votes to do it, but the Senate rules have prevented us from getting to a vote. We aren't giving up yet."

Sanford's tax plan would lower the state's highest income tax bracket by .225 percentage points a year for 10 years, lowering the rate from 7 percent to 4.75 percent.

For two days, Senate Democrats, led by John Land of Manning, fought to keep the proposal from the floor. Land and his supporters survived three attempts to end the filibuster Wednesday. The closest Republicans came to ending the filibuster was 25 votes, three short of the needed 28.

"They didn't want to win this," Land said. "They knew what a bad idea this was. We just did the governor a big favor. We kept him from doing serious damage."

For months, Sanford's proposal crept through the Senate. Fearing it might not be addressed by the end of the session June 3, Republican senators forced the issue, attaching it to a bill from the House.

The move let the governor's plan bypass the committee process and come up first on the Senate calendar. Some senators expected a showdown Tuesday, but too few supporters stayed in the chamber to break the Democrats.

Supporters of the governor's plan avoided that problem Wednesday by invoking a measure preventing any senator from leaving the chamber until the debate ended.

Despite their best efforts to wait out Democrats, the Republicans ended the struggle when it became clear they were not going to win.