House Speaker J. Dennis Hastert (R-Ill.) has acknowledged that President Bush's call for completion of a Social Security bill this year could be unrealistic and that the legislation might have to wait until 2006.

The president's aides immediately responded by saying Bush is committed to winning passage this year. The White House and Republican congressional leaders have said repeatedly that the proposed restructuring of the retirement system is doomed if it does not pass this year, because it will be even more difficult to get Democratic support in 2006, a midterm election year.

GOP lawmakers have also said Bush needs to sign the bill this year because they want close to a full year before the election to explain what they have done, and for retirees to see they are still getting their checks and scheduled increases.

But Hastert, in an interview to be published today by the National Journal, cast doubt on the ability of Congress to deliver on such a rapid schedule. He was asked what his timetable is for completion of a Social Security bill.

"Politically, we probably need to get something done by next spring, a year from now," he said. "You can't carry it right up to an election. That's just political dynamite."

The speaker's assessment reflects the realization by Republican lawmakers that Bush's proposal, featuring individual stock and bond accounts for workers younger than 55, has yet to gain momentum despite weekly barnstorming by Bush.

House leadership aides said House leaders still want the Senate to pass a plan first, meaning that it might be difficult for both chambers to act on such momentous legislation, then reconcile their two versions, by year's end. 

Ron Bonjean, Hastert's communications director, said the speaker has not changed his position. "The speaker hopes for enactment of Social Security legislation by the end of the year." 

Senate Majority Leader Bill Frist (R-Tenn.) caused a furor in early March when he told reporters that he wanted to pass Social Security, but that in "terms of whether it will be a week, a month, six months or a year, as to when we bring something to the floor, it's just too early."

Sen. Rick Santorum (R-Pa.) took the rare step of issuing a statement rebuking his leader for even suggesting that success might not be realized this year. The next day, Frist went to the Senate floor and declared: "We need to do it this year -- not next year, but this year."

Hastert also has said that he wants to complete the bill this year, and that it will be harder next year. In his comments to the National Journal, he made it plain that Congress has more selling to do, even before it begins grappling with the painful choices involved in addressing projected revenue shortfalls as baby boomers retire.

"When you are dealing with Social Security, there is always a nervousness," the speaker said. "This is something that you have to convince people that there really is a problem. . . . You can't take their Social Security, mash it up, and not have a good result."

Hastert added in the interview, conducted Monday, that he feels "cautiously optimistic that we can get this thing done."

"Most members, down in their heart, know that what we are trying to do is the right thing to do," he said. "It's a question of whether it's convenient politically, or whether they can stand the test back home. We have organized resistance on this thing, and you have to get through that." 

Bush aides continued to emphasize urgency. Rob Nichols, the chief Treasury Department spokesman, said: "We are committed to working with Congress to pass bipartisan legislation that strengthens and secures Social Security for future generations this year."