Oct. 21 (Bloomberg) -- John McCain is withholding endorsement of another economic stimulus package for the sagging U.S. economy, giving Barack Obama a fresh opening to attack him on the top issue in the presidential campaign.

With two weeks until Election Day, the idea -- advanced by Obama and other congressional Democrats -- that lawmakers should enact legislation to boost the economy gained traction when it won support from Federal Reserve Chairman Ben S. Bernanke and the Bush administration said it is ``open'' to proposals.

McCain said the best way to stimulate the economy is to enact his plan for the government to purchase troubled mortgages. McCain also wants to wait to see the impact of the $700 billion financial rescue plan passed earlier this month, his top economic adviser said.

``The Democrat-controlled Congress will likely propose additional measures,'' McCain and his running mate, Alaska Governor Sarah Palin, said in a statement. ``We do not believe that a national crisis should be taken as a license for wasteful spending or earmarked projects.''

With polls showing most people have more confidence in Obama to handle the economy, McCain is being put on the spot to focus on that topic and convince voters he has a better plan to pull the U.S. out of its slump.

`Fiscal Discipline'

McCain and Palin said any new proposals needed to support business sales and job creation and be ``consistent with long- term fiscal discipline.''

``He looks forward to any proposals and would evaluate them on their merits,'' Douglas Holtz-Eakin, his top economic adviser, said today in an interview.

At a speech today in Pennsylvania, the Republican senator from Arizona continued to attack Obama's tax plan, which the Democratic nominee says would reduce taxes for those making less than $250,000 a year. Rates for those with taxable incomes of more than $250,000 would return to levels in the 1990s, going to 36 percent and 39.6 percent from the current 33 percent.

``Obama's plan to raise taxes on some in order to give checks to others, it isn't a tax cut,'' McCain said. ``It's just another government giveaway. We've seen too much of that already.''

`Willful Ignorance'

Obama, meanwhile, accused McCain of offering ``little more than willful ignorance, wishful thinking and outdated ideology'' when it comes to aiding middle-income Americans.

The stimulus discussion was revived yesterday by Bernanke, who told a congressional committee the idea is ``potentially helpful and worthwhile.''

``With the economy likely to be weak for several quarters and with some risk of a protracted slowdown, consideration of a fiscal package by the Congress at this juncture seems appropriate,'' Bernanke said in prepared remarks before the House Budget Committee.

White House spokeswoman Dana Perino said today that while President George W. Bush ``remains open to listening to all good ideas'' from Congress on a stimulus package, the administration isn't planning to propose its own plan. She added that the $700 billion financial rescue package signed earlier this month is the best way to help the economy.

``We should let the process work,'' she said.

First Stimulus Bill

Bush in February signed into law a $168 billion measure that sent tax rebates of as much as $600 to individuals and $1,200 to couples. Checks went to 111 million households beginning in May.

Obama, campaigning today in Florida, repeated his call for a second stimulus package. The Illinois senator has proposed $50 billion in spending that included $25 billion for school repairs, roads and bridges, in addition to $500 checks for consumers to offset a rise in energy costs.

The House of Representatives approved a $56 billion stimulus package last month that was blocked in the Senate by Republicans. The plan would have extended unemployment assistance and increased spending on food stamps, highway and other infrastructure work and aid to state governments.

McCain supports the extension of unemployment benefits. Holtz-Eakin said. The candidate is less certain, though, that infrastructure spending would be effective in boosting the economy.

While there is a ``clear need'' to address the economy beyond the financial markets, ``the devil is in the details,'' he said. ``If there are genuinely effective projects that would be great.''

Mortgage Purchases

McCain instead is relying on his call for the government to purchase troubled mortgages using almost half of the $700 billion rescue plan, Holtz-Eakin said.

``That would put people into mortgages that they could handle, allow them to continue the rest of their household purchases and finally put a stop to the downward spiral in housing values,'' he said. ``That would be a tremendous stimulus to the economy.''

Obama said today that McCain's plan does ``nothing'' to create jobs and help families deal with emergencies and falling wages. He reiterated criticisms that McCain's housing plan is a ``$300 billion bailout for Wall Street banks'' because it buys troubled loans directly from lenders at face value.

Obama spoke today at Palm Beach Community College in Lake Worth, Florida, before holding a roundtable discussion on the economy with former Federal Reserve Chairman Paul Volcker and other politicians and business leaders.

McCain is spending the day in Pennsylvania, with rallies around the state.

Florida and Pennsylvania are two of the biggest targets for both campaigns, with a combined 48 of the 270 electoral votes needed to win the White House. Both states saw payrolls shrink in September. Florida's unemployment rate rose to 6.6 percent from 4 percent last year. Pennsylvania's unemployment rose to 5.7 percent from 4.5 percent.

To contact the reporters on this story: Matthew Benjamin in Washington at mbenjamin2@bloomberg.net;

Last Updated: October 21, 2008 19:12 EDT