Obama campaign calls McCain ad a 'lie'

[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/images/09/08/art.palin.bridge.gi.jpg caption="New McCain television ad claims Republican VP candidate Sarah Palin stopped the “Bridge to Nowhere”."]

(CNN) - The presidential campaigns of Barack Obama and John McCain are sparring over a new television ad claiming Republican VP candidate Sarah Palin stopped the “Bridge to Nowhere” - the infamous $400 million congressional earmark that became the ultimate symbol of excessive pork-barrel spending.

Watch: The McCain campaigns latest ad, 'The Original Mavericks'

The new McCain ad, set to air in key states, calls both the Arizona senator and Palin "original mavericks," and characterizes the Alaska governor as an ardent opponent of the 2005 bridge proposal championed by Alaska Sen. Ted Stevens connecting Ketchikan, Alaska to the Ketchikan airport on Gravina Island (Population: 50).

Several opponents of Palin, as well as the non-partisan factcheck.org, have noted the claim she was against the bridge is not entirely accurate - the Alaska governor was for the bridge during her 2006 gubernatorial bid, and did not begin opposing it until it became clear the project was doomed on Capitol Hill.

Obama campaign spokesman Bill Burton went even further Monday, calling the assertion a flat out "lie."

“Despite being discredited over and over again by numerous news organizations, the McCain campaign continues to repeat the lie that Sarah Palin stopped the Bridge to Nowhere," Burton said. "McCain and Palin will say or do anything to make people believe that they will change something besides the person sitting in the Oval Office."

But McCain spokesman Brian Rogers is standing by the claim, and said the Obama campaign is launching "hysterical attacks."

“The only people ‘lying’ about spending are the Obama campaign," Rogers said. "The only explanation for their hysterical attacks is that they’re afraid that when John McCain and Sarah Palin are in the White House, Barack Obama’s nearly $1 billion in earmark spending will stop dead in its tracks."

Rogers also provided several press clips noting Palin became a critic of the bridge in her early days as governor of Alaska.

UPDATE: The McCain campaign says the Alaska Democratic Party has removed a Web page that credited Palin for killing the Bridge to Nowhere project.

"National Democrats apparently want to rewrite history and say that Palin did not kill the Bridge to Nowhere," the McCain campaign's Michael Goldfarb said.