CHICAGO (Reuters) - Democrat Barack Obama on Monday called on voters to “turn the page” on the policies of the Bush administration as he emphasized his message of change in a closing argument for the presidential campaign.

With eight days left before Election Day, the Illinois senator laid blame for the deepening financial crisis on U.S. President George W. Bush and said Republican presidential candidate John McCain’s approach on the economy would mirror Bush’s.

“Sen. McCain has served this country honorably. And he can point to a few moments over the past eight years where he has broken from George Bush -- on torture, for example,” Obama said in excerpts from a speech he is to deliver later in Canton, Ohio.

“He deserves credit for that. But when it comes to the economy -- when it comes to the central issue of this election -- the plain truth is that John McCain has stood with this president every step of the way,” Obama said.

The Ohio speech has been billed by the Obama campaign as a “closing argument” for the candidate and one he will emphasize in a 30-minute prime-time television advertisement on Wednesday.

Slideshow ( 12 images )

Obama, seeking to become the first black U.S. president, is leading McCain in both national opinion polls and in surveys of many of the crucial battleground states that will decide the election.

Obama held steady with a 5-point lead over McCain among likely U.S. voters nationally in a Reuters/C-SPAN/Zogby national tracking poll released on Monday.

McCain, an Arizona senator, has described himself and running mate Sarah Palin as mavericks and said he has shown a willingness throughout his career to break with his Republican Party, including with Bush. McCain has said Obama does not have a track record of bucking his own party.

But Obama took at aim at McCain’s proposal for cuts in corporate tax rates and his opposition to rolling back the Bush tax cuts on the wealthiest Americans, saying they represented a “tired, old” approach on the economy.

“In one week, you can turn the page on policies that have put the greed and irresponsibility of Wall Street before the hard work and sacrifice of folks on Main Street,” Obama told voters.