A new ad by John McCainJohn Sidney McCainOvernight Defense: GOP lawmaker takes unannounced trip to Syria | Taliban leader pens New York Times op-ed on peace talks | Cheney blasts paper for publishing op-ed GOP lawmaker makes unannounced trip to northeastern Syria Meghan McCain after Gaetz says Trump should pardon Roger Stone: 'Oh come on' MORE's campaign tries to tie Barack ObamaBarack Hussein ObamaFive takeaways from new fundraising reports for 2020 Democrats Obama sends birthday wishes to John Lewis: 'Thanks for making good trouble' The Hill's Campaign Report: Warren up, Bloomberg down after brutal debate MORE to Chicago politicians enmeshed in ethics controversies.

The ad features a clip of Obama saying that he hails from Chicago, followed by photos of Illinois Gov. Rod Blagojevich (D), Chicago Mayor Richard Daley (D) and convicted felon and fundraiser Antoin Rezko.

"Barack Obama, born of the corrupt Chicago political machine," a narrator intones.

McCain's campaign said the ad will run nationally, but it didn't say how much it would spend to air it and whether it would run on broadcast or cable channels.

Obama's campaign has called the spot "false" and highlighted a report that McCain's campaign manager, Rick Davis, was paid to lobby on behalf of embattled mortgage companies Fannie Mae and Freddie Mac.

"It's no coincidence that on the very day newspapers reported that John McCain's campaign manager was paid $2 million to lobby against tighter regulation of Fannie Mae and Freddie Mac, the McCain campaign would launch this false, gratuitous attack," said Obama spokesman Bill Burton in a statement. "Barack Obama was elected to the Illinois Senate as an independent Democrat. He took on the Chicago Democratic organization in a primary to win a seat in the US Senate. And in both Illinois and Washington, he has challenged the Old Guard for landmark ethics reforms."

Read the ad's transcript and watch the ad below.

Script For "Chicago Machine" (TV :30)

ANNCR: Barack Obama.

Born of the corrupt Chicago political machine.

BARACK OBAMA: In terms of my toughness, look first of all, I come from Chicago.

ANNCR: His economic adviser, William Daley. Lobbyist. Mayor's brother.

His money man, Tony Rezko. Client. Patron. Convicted Felon.

His "political godfather." Emil Jones. Under ethical cloud.

His governor, Rod Blagojevich. A legacy of federal and state investigations.

With friends like that, Obama is not ready to lead.

JOHN MCCAIN: I'm John McCain and I approve this message.