President Barack Obama plunges into a difficult test of his leadership this week, struggling to get a divided Congress to agree on his economic recovery package while pitching a new plan to ease loans to consumers and businesses.

The Senate’s $827 billion stimulus legislation seems assured narrow passage by Tuesday. Harder work for Obama and the Democrats comes in the days ahead, when the House and Senate attempt to reconcile differences in their two versions.

Obama and Democratic Party leaders had hoped to have a bill ready for the president’s signature by Feb. 16, a goal that appears increasingly unlikely.

At the Treasury Department, Secretary Timothy Geithner delayed the unveiling of a new bailout framework for financial institutions from Monday to Tuesday. Geithner is considering steps to broaden the use of a new lending facility at the Federal Reserve, provide government guarantees to help banks deal with their troubled assets, and continue direct infusion of capital into banks in exchange for securities and tougher accountability rules.

For Obama, the economy has become a two-front engagement, with one effort aimed at creating or saving jobs and the other at unfreezing the credit markets. Amid the urgency created by nearly 600,000 new unemployed workers last month and new bank failures, Obama’s economic prescriptions are coming under critical scrutiny by both Congress and the American public.

The House and Senate bills are about $7 billion apart in cost and overlap in numerous ways. But the Senate bill has a greater emphasis on tax cuts, while the House bill devotes more money to states, local governments and schools.

Lawrence Summers, Obama’s top economic adviser, signaled the struggle ahead as he made the rounds of Sunday morning talk shows. “There are crucial areas, support for higher education, that are things that are in the House bill that are very, very important to the president,” he said on ABC.

Rep. Barney Frank of Massachusetts, the Democratic chairman of the House Financial Services Committee, warned that reductions in state spending in the Senate bill would hurt local communities.

“To get any Republicans at all, you had to adopt a cut that’s going to mean policemen and firemen are going to be laid off,” he said. “Aid to the states is to prevent this budget crunch from laying off public employees.”

Sen. John Ensign of Nevada, a member of the Senate Republican leadership, dismissed Frank’s complaint as “fear-mongering.”

The Senate bill is finely tuned. With only two or three Republicans on board, it is guaranteed, at most, 61 votes; the bill needs 60 votes to advance and avoid procedural hurdles. Any change in the balance struck by the Senate bill could doom it.

Obama will take his case to the American people Monday with his first prime-time news conference. He’ll also participate in town hall-style meetings in cities suffering particularly hard times, Elkhart, Ind., on Monday and Fort Myers, Fla., on Tuesday.

Americans United for Change, a liberal advocacy group that had run a radio ad pressing Sen. Arlen Specter of Pennsylvania to support Obama’s stimulus plan, changed its tone Sunday and announced a new ad thanking Specter for helping work out the Senate compromise. The group also planned to air ads in Maine thanking Republican Sens. Susan Collins and Olympia Snowe, who are also expected to support the Senate bill.

The House and Senate are scheduled to go on recess next week, but congressional leaders have said they will not leave until the bill is completed.

The bank bailout proposal that Geithner will announce Tuesday also carries policy and political risks. Congress approved a $700 billion bailout for the financial sector last fall. But since then, lawmakers from both parties have been critical of how the Bush administration spent the first half of the money.

The Senate grudgingly agreed to give Obama access to the second half of the fund, but only after Obama promised to impose tougher conditions and to devote at least $50 billion of the fund to reducing mortgage foreclosures.

Officials said Geithner will not ask for more money for the program at this point. Instead, his plan is likely to include various approaches to loosening credit and helping banks deal with troubled, mortgage-backed assets.

“We are going to solve it by being as effective and strategic as we possibly can in the use of public money so as to catalyze and spur private investment,” Summers said Sunday. He appeared to be describing one plan under consideration that that would have the government put up seed money to attract private-sector buyers to take on some of the banks’ troubled assets.

Other options, cited by industry and congressional officials:

Continuing to stress government purchases of bank stock as a way to bolster banks’ balance sheets and try to get them to resume more normal lending. The money would come with more strings attached than in the past.

“Institutions that get assistance will have to participate in loan modifications and meet other standards that we set,” Geithner told House Democrats at a party retreat in Williamsburg, Va., on Saturday, according to notes taken by party officials.

Expanding the use of the Term Asset-Backed Securities Loan Facility, a new program the Federal Reserve is developing, beyond supporting consumer loans to other types of lending. The Fed on Friday announced new terms and conditions for the facility and said a starting date would be announced later this month.