WASHINGTON » President Barack Obama is pushing in his weekly radio and Internet address for Senate passage of his nearly $450 billion jobs bill as senators prepare to vote Tuesday on moving to debate on the measure.

Obama also asked listeners to Saturday’s address to tell their senators to support the bill, which he’s been lobbying for aggressively against Republican opposition since unveiling it a month ago.

With the economy listless and unemployment stuck above 9 percent moving into the 2012 presidential campaign, Obama said the bill "can help guard against another downturn here in America."

"But if we don’t act, the opposite will be true," the president said. "There will be fewer jobs and weaker growth. So any senator out there who’s thinking about voting against this jobs bill needs to explain why they would oppose something that we know would improve our economic situation."

Obama’s jobs plan would reduce payroll taxes on workers and employers, extend benefits to long-term unemployed people, spend money on public works projects and help states and local governments keep teachers, police officers and firefighters on the job.

He proposed paying for the plan mainly by closing tax loopholes for oil and gas companies and raising taxes on individuals making more than $200,000 a year and couples making more than $250,000. Those proposals were rejected by Senate Democrats who substituted a tax on millionaires, with Obama’s agreement.

But with Republicans opposed to much of the new spending in the bill and to tax hikes even on millionaires, the legislation stands no chance of getting through the Republican-controlled House in its current form, even if Senate Democrats were able to muster the necessary Republican support for Senate passage.

Despite the opposition Obama intends to keep pushing for the plan in an effort to show the public that Republicans are standing in the way.

"The proposals in this bill are steps we have to take if we want to build an economy that lasts; if we want to be able to compete with other countries for jobs that restore a sense of security for the middle-class," Obama said.

"There are too many people hurting in this country for us to simply do nothing," he said. "The economy is too fragile for us to let politics get in the way of action." Despite opposition to the overall bill, individual elements of it may well get through Congress, particularly an extension and expansion of a payroll tax cut that took effect Jan. 1.

Republicans used their weekly address to criticize the plan.

Sen. John Thune, R-S.D., called it "nothing but a rehash of the same failed ideas he’s already tried, combined with a huge tax increase."

"This is a cynical political ploy that’s designed not to create jobs for struggling Americans, but to save the president’s own job," Thune said.

He also accused Obama of promulgating excessive regulations and too much red tape, to the detriment of business.

"We’re calling for a regulatory time-out, an affordable energy plan, broad-based tax reform including lower rates, and policies that provide the certainty and stability our economy desperately needs," Thune said.