UPDATE 2-Republicans seize on Biden middle class comment ahead of debate

* 'Buried' remark comes day before first Obama-Romney debate

* Voters rate U.S. economy No. 1 issue ahead of Nov. 6 election

(Adds more Biden comment, Ryan, new campaign comment, paragraphs 5, 8-10.)

By Patricia Zengerle

WASHINGTON, Oct 2 (Reuters) - U.S. Vice President Joe Biden told a campaign rally on Tuesday that the middle class has been buried for the past four years, just longer than President Barack Obama's time in the White House.

Republicans immediately seized on what they termed a "stunning admission" by Biden as evidence that Obama's policies have been bad for the economy, the day before Obama and his Republican challenger Mitt Romney meet in their first presidential debate.

Discussing what the Obama campaign contends are Romney's plans to raise taxes on most Americans to fund tax cuts for the wealthy, Biden made his comment in an emotional speech to a crowd in Charlotte, North Carolina.

"This is deadly earnest. How they can justify ... raising taxes on the middle class that has been buried the last four years? How in the Lord's name can they justify raising their taxes and these tax cuts?" he asked.

"We've seen this movie before - massive tax cuts for the wealthy, eliminating restrictions on Wall Street, let the banks write their own rules. We know where it ends. It ends in the catastrophe of the middle class and the Great Recession of 2008. Folks, we cannot go back to that. The president and I have a different way forward," Biden said.

Voters say the struggling U.S. economy is the most important issue in the election, and Obama's Democrats and Romney's Republicans have been jockeying over who would be better economic stewards for average Americans.

"Under President Obama, the middle class has suffered from crushing unemployment, rising prices and falling incomes," Amanda Henneberg, a Romney spokeswoman, said in a statement.

"Vice President Biden, just today, said that the middle class, over the last four years, has been 'buried.' We agree," Romney's running mate, Paul Ryan, told supporters at a campaign event in Iowa.

Obama's campaign fired back that Romney's camp was making a "desperate and out-of-context attack."

"As the vice president has been saying all year and again in his remarks today, the middle class was punished by the failed (former President George W.) Bush policies that crashed our economy - and a vote for Mitt Romney and Paul Ryan is a return to those failed policies," camp aign spokeswoman Lis Smith said in a statement.

The U.S. presidential election is Nov. 6.

(Editing by Cynthia Osterman and Stacey Joyce)


Messaging: patricia.zengerle.reuters.com@reuters.net))