Washington (CNN) -- President Barack Obama sent a tough message to Republicans on Thursday, ahead of an expected Senate battle over his $447 billion jobs bill.
"As we look towards next week, any senator out there who's thinking about voting against this jobs bill when it comes up for a vote needs to explain exactly why they would oppose something that we know would improve our economic situation at such an urgent time for our families and for our businesses," Obama said at a news conference.
The president said the "problems Europe is having today could have a very real effect on our economy at a time when it's already fragile. But this jobs bill can help guard against another downturn if the situation in Europe gets any worse. It'll boost economic growth, it'll put people back to work."
"This jobs bill is fully paid for by asking millionaires and billionaires to pay their fair share," Obama said. "Some see this as class warfare. I see it as a simple choice: We can either keep taxes exactly as they are for millionaires and billionaires, with loopholes that lead them to have lower tax rates, in some cases, than plumbers and teachers, or we can put teachers and construction workers and veterans back on the job."
The bill introduced by Senate Majority Leader Harry Reid on Wednesday night includes a so-called "millionaire's surtax," a separate 5.6% tax on income over $1 million.
A Senate Democratic leadership aide said the surtax would raise more than enough to pay for the jobs bill within the required 10-year window.
The tax hike would kick in in 2013, rather than 2012 as previously proposed.
"It satisfied our caucus' desire for this surtax on millionaires to pay for (the jobs plan) and is consistent with the president saying no tax increases in 2012," a Senate Democratic leadership aide told CNN.
Asked about the surtax, Obama said, "The approach that the Senate is taking I'm comfortable with, in order to deal with the jobs bill. We're still going to need to reform this tax code to make sure that we're closing loopholes, closing special-interest tax breaks, making sure that the very simple principle, what we call the Buffett rule, which is that millionaires and billionaires aren't paying lower tax rates than ordinary families -- that that's in place.
"So there's going to be more work to do with respect to making our tax system fair and just and promoting growth, but in terms of the immediate action of getting this jobs bill passed, I'm fine with the approach that they're taking."
Republicans struck back.
"We will not stand for a permanent tax hike for a temporary stimulus that is largely a rehash of the same failed stimulus ideas," the press office of Senate Minority Leader Mitch McConnell quoted the Kentucky Republican as saying.
House Speaker John Boehner, meanwhile, released a new "infographic" arguing that the White House effort to pass the bill includes all sorts of ideas -- but not working with House Republicans.
"With the White House failing to make any headway with job creators, the American people, and Senate Democrats, will President Obama finally work with Republicans to find common ground on removing barriers to job growth?" asks a post written by three people on Boehner's official blog.
Boehner also accused Obama of campaigning for re-election instead of governing.
Two key centrist senators announced they oppose the surtax.
Sen. Scott Brown of Massachusetts, a moderate Republican who has voted with Democrats and is up for re-election, said he will not support the surtax because he believes it's being offered by Democrats in a politically inspired environment. Brown argued that broad tax reform is needed.
Sen. Ben Nelson of Nebraska, a moderate Democrat who often votes against his party and is also up for re-election, said he opposes higher taxes.
Obama argued that Congress must act.
Asked if he was trying to run against a "do-nothing Congress," Obama said: "If Congress does something, then I can't run against a do-nothing Congress.
"If Congress does nothing," the president added, then "I think the American people will run them out of town."
The president acknowledged that "there is no doubt" that economic growth has slowed and that the economy is "weaker now than it was at the beginning of the year," when people were more optimistic.
The Japanese tsunami; the Arab Spring, which drove up gas prices; and economic problems in Europe have caused concerns, he added.
"And we did not help here in Washington with the debt ceiling debacle."
Obama said many of the problems the economy faces predate the financial crisis, as middle-class families have seen their wages and incomes remain flat despite rising costs.
"So folks have been struggling not just for the last three years. They've been struggling for over a decade," he said. "We have to take action that is big enough to meet the moment."
Obama also stressed the need for measures to protect Americans from reckless actions by some in the financial sector, and criticized some who have fought regulatory changes "every inch of the way" and are now pushing for reforms to be rolled back.
Banks should not be finding ways to make consumers pay for reforms, such as by inventing new hidden fees, he said, and the government has a role in preventing unfair practices.
The president spoke as the protest movement Occupy Wall Street was expanding to other cities.
The protesters "are giving voice to a more broad-based frustration about how our financial system works," Obama said.
"We have to have a strong, effective financial sector in order for us to grow," the president said, but he added that regulations and government oversight are critical.
"And what we've seen over the last year is not only did the financial sector, with the Republican Party in Congress, fight us every inch of the way, but now you've got these same folks suggesting that we should roll back all those reforms and go back to the way it was before the crisis."
The president's top advisers have said they aim to present a unified Democratic front on jobs.
CNN's Brianna Keilar, Kate Bolduan, Diane Ruggiero, Ted Barrett, and Josh Levs contributed to this report.