DAYTON, September 9, 2008 (AFP) - Democrat Barack Obama Tuesday assailed his Republican White House rival John McCain's claim to be an agent of change, arguing he had done nothing in three decades in Congress to improve US schools.

In excerpts from a speech here detailing his own plans to improve public education, Obama zeroed in on an issue of major concern to voters worried about failing schools and soaring university tuition costs.

'In the past few weeks, my opponent has taken to talking about the need for change and reform in Washington, where he has been part of the scene for about three decades,' Obama said of McCain, a 26-year veteran of Congress.

'And in those three decades, he has not done one thing to truly improve the quality of public education in our country. Not one real proposal or law or initiative. Nothing,' the Illinois senator said.

The attack came a day after Obama accused McCain and the Republican's running mate Sarah Palin of 'shameless' dishonesty with their claim to be 'mavericks' who are distinct from the unpopular President George W. Bush.

The rhetoric has turned more biting as polls show McCain, helped by conservative excitement at the addition of Alaska Governor Palin as his vice presidential nominee, pulling even or ahead in the race for November 4's vote.

The Obama campaign released a new advertisement accusing McCain of planning to cut education funding while extending hefty tax breaks to big companies, and proposing to abolish the Department of Education.

'We can't afford more of the same,' the ad said, tying McCain and Palin to Bush despite the Republicans' self-professed claim to be zealous reformists who would take on special interests in Washington.

'That is not my idea of reform. That is not my idea of change. That is not a plan to help your kids compete with those kids in China and India,' Obama was to say in his speech at a Dayton high school.

'After three decades of indifference on education, do you really believe that John McCain is going to make a difference now?'

McCain favors giving parents vouchers to send their children to the state school of their choice, and accuses Obama of being beholden to powerful teachers' unions to the detriment of pupils' education needs.

The Democrat said he would couple higher pay for teachers with more exacting standards. Educators performing poorly would get support, 'but if they still don't improve, they'll be replaced,' he vowed.