Former House speaker Newt Gingrich (R-Ga.) on Tuesday preempted his own campaign suspension, announcing in a video to supporters that he will pull out of the presidential race on Wednesday.

“I want to take this opportunity to give you an insider advance notice that on Wednesday, I’ll be officially suspending the campaign as part of a press event,” Gingrich says in the preannouncement announcement. “I wanted you to know first because your help was vital.”

Gingrich is expected to formally end his campaign at an event in Northern Virginia .

Also in the area on Wednesday will be former Massachusetts governor Mitt Romney. But the GOP frontrunner and his onetime foe aren’t expected to make a joint appearance – not yet, anyway.

In his farewell video, Gingrich tells supporters reelecting the president “would be a genuine disaster.”

“All of us have an obligation, I think, to do everything we can to defeat Barack Obama,”he says.

And he pledges that both he and his wife, Callista, will be “talking, campaigning, making speeches – doing everything we can to help defeat Barack Obama.”

One person Gingrich doesn’t mention in the video is Romney. Gingrich, like former senator Rick Santorum (R-Pa.), who also pulled out of his GOP primary campaign, has yet to formally pledge his support to Obama’s challenger.

(Our colleagues Al Kamen and Karen Tumulty flagged something a little off about the video here.)