(Image Credit: Chris Kleponis/AFP/Getty Images; Paul J. Richards/AFP/Getty Images)

The super PAC backing President Obama has joined an intensifying battleground state skirmish over high gas prices and oil company subsidies.

A new TV ad by Priorities USA Action links Mitt Romney to the U.S. oil industry, which it claims has been underwriting the assault on Obama to defend billions of dollars in taxpayer cash.

"Who's behind this ad smearing President Obama? Big Oil, that's who," says the narrator in the 30-second spot that's airing in eight states - Colorado, Florida, Iowa, Michigan, New Mexico, Nevada, Ohio and Virginia.

"The money they make from high gas prices - is going right into Mitt Romney's campaign," the ad says.

Romney opposes eliminating tax incentives and subsidies for the major U.S. oil companies, even as they have reported record profits in recent months.  Obama wants to end the practice and invest the money on development of renewable energy sources instead.

The American Energy Alliance, a nonprofit group with Republican ties, has been blasting Obama's energy policy with a $3.6 million TV ad campaign in the same eight states, which are all crucial for the general election.

The ad - "Nine dollar gas" - criticizes Obama for gas prices that have nearly doubled during his first term as he has opposed oil drilling in Alaska and construction of the Keystone XL pipeline and backed support for a $500 million loan to solar start-up Solyndra, which later went bankrupt.

It also features a quote from Obama Energy Secretary Steven Chu who said before taking office in 2008 that the country needs to "boost the prices of gasoline to levels in Europe."  He has since reiterated a commitment to bringing down prices.

"Tell Obama: We can't afford his failing energy policies," the AEA ad says.

Crossroads GPS, another pro-Republican interest group ran a similar TV ad campaign in New Mexico, Ohio and Nevada last month, spending $650,000 to hit Obama on oil production and the Keystone pipeline.

Democrats say the offensive by both groups is funded in part by conservative billionaire oil company magnates Charles and David Koch, who have pledged more than $200 million to defeating Obama. Neither organization however is required by law to reveal the identities or contribution amounts of its donors.

Obama has been promoting his "all-of-the-above" approach to energy production, which has overseen the highest levels of domestic oil production in eight years. As part of that strategy, he has urged Congress to repeal $4 billion in subsidies for the oil industry. But in a vote last week, the Senate rejected the proposal.

Republicans insist repealing the subsidies amounts to a tax hike on oil companies, which would in turn raise prices at the pump even higher.