The U.S. Chamber of Commerce on Thursday launched a new get-out-the-vote effort, sending a video to members and dropping its first piece of direct-mail in the general election, attacking Democratic Massachusetts Senate candidate Elizabeth Warren.

The chamber emailed the following video message from Chamber President and CEO Tom Donohue to member businesses:

The chamber says it will reach 7 million members, distributing payroll stuffers, posters, and postcards for businesses to turn out employees and sway their votes.

On top of TV and radio ads already airing, the chamber today issued its first attack mailer of the 2012 general election, the group told ABC News. The chamber had already sent a mailer in support of Sen. Dick Lugar's losing effort in his Indiana Senate primary; but today it sent this direct-mail piece to targeted registered voters in Massachusetts, where Warren is challenging incumbent GOP Sen. Scott Brown.

The mailer calls Warren "catastrophically antibusiness":