Chicago (AP) John McCain's energy policies come under attack today in a new Barack Obama campaign ad.

The ad claims that McCain, like President Bush who worked in the oil industry, would be “in the pocket of big oil.” it opens with a driver pumping gas. The announcer says, “every time you fill your tank, the oil companies fill their pockets.”

Obama's spot trumpets his proposal to revive a windfall profits tax on energy companies and asserts that McCain favors tax breaks for the oil industry.

Obama has pushed for such a tax to fund $1,000 emergency rebate checks for consumers besieged by high energy costs.

Congress enacted a windfall profits tax in 1980, during an earlier era of high oil prices, but repealed it in 1988 amid concerns the tax was discouraging domestic oil development.

Obama hopes to emphasize energy and the economy in campaign stops this week in michigan, Ohio and Indiana.