WASHINGTON (CNN) -- Republicans say Sen. John McCain and his vice presidential running mate, Sarah Palin, are mavericks. But in a new ad, Sen. Barack Obama's campaign says not so fast -- they're no maverick reformers.

Sen. John McCain has been criticized for employing top lobbyists in his campaign.

And it's a point that Obama has been making on the campaign trail in recent days.

"John McCain says that he is going to tell all those lobbyists in Washington that their days of running Washington are over, which sounds pretty good until you discover that seven of his top campaign managers and officials are -- guess what? -- former corporate lobbyists," Obama said recently in Flint, Michigan.

It's true: Seven top McCain officials were lobbyists, though the campaign stresses that none is currently registered to lobby Congress:

• One: Campaign manager Rick Davis is a major telecommunications lobbyist.

• Two: Senior foreign policy adviser Randy Scheunemann recently faced scrutiny over his foreign lobbying on behalf of the Republic of Georgia, which has been embroiled in a military conflict with Russia.

• Three: Senior adviser Charlie Black was a foreign lobbyist for dictators in Zaire and Angola in the 1980s, fodder for the liberal group MoveOn.org.

One of the group's recent ads charged, "Charlie Black said he didn't do anything wrong. John McCain should tell Black he did. Call John McCain and tell him to fire Charlie Black." Watch the Republicans' ad calling McCain-Palin mavericks »

• Four: Frank Donatelli, the Republican National Committee's liaison to the McCain campaign, has had clients including Exxon Mobil.

• Five: Economic adviser Nancy Pfotenhauer has lobbied for corporate giants like Koch Industries.

"Both John McCain and Sarah Palin have challenged special interests, challenged their own party. That's the test of courage," Pfotenhauer has said.

• The final two lobbyists are McCain's congressional liaison, John Green, and national finance Co-chairman Wayne Berman. They both lobbied for Fannie Mae, the troubled mortgage giant.

But Obama's case could be undermined by running mate Sen. Joe Biden's close ties to lobbyists, including his son Hunter, who has worked for credit card giant MBNA.

Biden insists that his son's employment had nothing to do with his support of bankruptcy legislation backed by the bank. Watch Palin criticize Biden's change argument »

"I can look you right straight in the eye and guarantee you my son has never, ever, ever lobbied me," Biden said on CNN's "American Morning" on September 4.

The McCain camp stresses that Donatelli and Berman are technically not officials of the campaign, though they are advisers.

But the bottom line is, both sides have ties to lobbyists, meaning whomever wins will have a hard time backing up the rhetoric about change and shaking up Washington.

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