TVNewser hears networks are preparing for the news of a possible John Edwards endorsement of Sen. Barack Obama tonight. If it does happen, it sets the stage for a possible prime time live speech from the former Democratic presidential nominee.

Edwards hinted at a possible Obama endorsement when he appeared on MSNBC's Morning Joe last week.

A network insider says the channel is making preparations for how to break the news.

• Update: All three cable networks are now reporting Edwards' endorsement of Obama. MSNBC was first with the news, at 5:13:20pmET. CNN was in commercial at the time, and reported the news about 30 seconds after MSNBC. FNC had the news at 5:15pmET. All networks MSNBC sourced the Associated Press with the news when breaking the news.

> More: ABC News was the first news organization to report the endorsement, with a blog post on Political Radar on ABCNews.com at 5:04pmET.