CNN  — 

Vice President Joe Biden will be invited to participate in the first Democratic presidential primary debate if he declares his intention to seek his party’s nomination as late as the day of the debate, eligibility criteria released Monday by CNN shows.

So far, Lincoln Chafee, Hillary Clinton, Martin O’Malley, Bernie Sanders, and Jim Webb have been invited to the first Democratic National Committee-sanctioned debate on Oct. 13 at the Wynn Las Vegas.

All five of the candidates have achieved an average of 1% in three polls, recognized by CNN, released between Aug. 1 and Oct. 10. The debate criteria was published Monday morning.

CNN previously named Anchor Anderson Cooper as the debate moderator. On Monday, CNN announced that Chief Political Correspondent Dana Bash and CNN en Español Anchor Juan Carlos Lopez will ask additional questions, and Anchor Don Lemon will present questions to the candidates submitted through Facebook during the two-hour primetime debate.

Biden, who has publicly struggled with deciding whether to join the primary, has met the minimum polling threshold for entry into the debate. He would only need to file the necessary paperwork with the Federal Election Commission or declare his intention to do so to appear on stage at the Wynn, according to the criteria.

Related: Biden unsure if he’s “there” for White House run

The DNC sanctioned debate is being hosted by CNN and Facebook and will air live at 9 p.m. ET on CNN, CNN en Español, CNN International, and streamed on CNNgo. Westwood One will serve as the exclusive radio broadcaster.