Updated

The Obama administration's latest get-the-economy-out-of-its-rut proposal will create jobs "immediately," the president says -- so long as immediately doesn't mean this year.

President Obama and his senior administration officials appeared to be reading from different scripts Monday as they offered projections for how a proposed $50 billion infrastructure investment would affect the economy.

The plan would pump money into road repair, railway construction and runway restoration. Speaking in Milwaukee, Obama said the package would "create jobs immediately" as well as "make our economy hum over the long haul."

But senior administration officials, speaking on a conference call with reporters just hours earlier, said the proposal was not designed to instantly gratify the jobs market and would probably not lead to any new jobs until 2011.

"This is not a stimulus-immediate jobs plan," one official said.

Officials said the proposal, which would front-load the money to create a "substantial number of jobs" during its first year, was aimed broadly toward long-term growth over its six years of funding.

"We're not like trying to put out an idea today that we think in October 2010 is going to create a lot of jobs that month," one official said. "That's not what the motivation for this was. That's not how this is designed. That's not what this is."

White House Press Secretary Robert Gibbs repeated Tuesday during his daily briefing that Obama's proposals are aimed at long-term growth over short-term gain.

Logistically, creating jobs immediately would seem a heavy lift -- something Republicans were quick to point out.

One GOP aide noted that the Senate, after returning from recess this month, will only be in session for a few weeks before adjourning for the elections. The brief in-session time will be devoted to a small business aid bill which Obama has pressed the chamber to pass in speech after speech, as well as other leftover appropriations legislation.

The aide said the Senate is going to need to review and, at a minimum, hold hearings on the infrastructure proposal in the Environment and Public Works and Finance committees.

Asked Tuesday whether Obama thinks he can pass the package before Election Day, Gibbs acknowledged the environment is tricky.

"We understand what season we've entered in Washington. We know that Congress won't be here for a lot of the time. We certainly hope that there are measures, including some of the ones that the president will outline, that Congress will consider," Gibbs said. "If they don't do that prior to the election, the president and the economic team still believe that these represent some very important ideas in continuing along our path toward economic recovery."

In the past few days, Obama has proposed passing the infrastructure package, allowing companies to write off 100 percent of their new capital investments through next year and permanently extending a business tax credit for research and development.