A story released today by the Associated Press reports that thwarted in their drive for final repeal of the estate tax, congressional Republicans are seeking permanent relief for married couples.

``We think we have a chance of making it permanent,'' Rep. Rob Portman, R-Ohio, said of the break that last year's GOP-sponsored tax cut granted to married couples.

House leaders were staging the debate the day after Senate Democrats engineered the defeat of the permanent repeal of the estate tax. The measure died Wednesday on a vote of 54-44, six shy of the total needed for passage under Senate rules.

Sen. Kent Conrad, D-N.D., called the repeal "the most irresponsible amendment'' offered in the Senate this year, saying it would grant tax relief to the superrich while raiding the Social Security trust funds.

Republicans, led by Sen. Phil Gramm, R-Texas, dismissed those claims, and President Bush issued a statement expressing his disappointment with the outcome on the Senate floor.

Bush's tax legislation, approved last year, cut a variety of levies, including the marriage penalty, which requires some couples to pay more in federal income taxes than they would if single. It also phased out the estate tax gradually over the next several years.

However, the overall tax bill expires on Jan. 1, 2011, meaning all the relief would vanish if Congress took no further action.

Bush has asked Congress to approve permanent extensions for all the provisions in the original bill, and the Republican-led House already has complied.

But that bill has languished in the Democratic-controlled Senate, and in response, House Republicans began passing portions of it piece by piece.

The so-called marriage penalty relief is the latest part of Republican tax cuts on the installment plan, to be followed shortly by a measure dealing with individual retirement accounts.

Gramm, nearing the end of an 18-year conservative's career, led the fight for estate tax repeal in the Senate.

Rebutting Democratic criticism, he said opponents of the repeal measure ``believe it is worth forcing people at the death of their parents to sell off their life's work to give half of it to the government.''

Democrats advanced two alternatives in the run-up to the final vote, both of which fell short of the 60-vote threshold.

One option, which got 38 votes, would have made the tax repeal permanent for all but the largest estates -- those over $3.5 million for individuals and $7 million for couples. The second, which gained 44 votes, would have added permanent relief for all family owned farms and small businesses.

The repeal measure was passed by the House last week on a vote of 256-171 and drew the support of 41 Democrats, an indication of the political potency of the issue in rural areas.

The bill gained backing from 45 Republicans and nine Democrats, including three who are on the ballot this fall -- Sens. Max Baucus of Montana, Max Cleland of Georgia and Mary Landrieu of Louisiana. Three other Democrats confronting tough re-election challenges -- Sens. Paul Wellstone of Minnesota, Jean Carnahan of Missouri and Tim Johnson of South Dakota -- voted for at least one of the Democratic alternatives.

Voting in opposition to the repeal were 41 Democrats, one independent and Republican Sens. Lincoln Chafee of Rhode Island and John McCain of Arizona.