(CNN) Democratic presidential candidates at risk of missing the September debate will have a longer window to qualify for the one in October.

In an email reviewed by CNN that was sent to a presidential campaign by the Democratic National Committee, the campaign was informed that qualifying polls for the October debate must have been released between June 28 and two weeks prior to the debate.

That polling window means that candidates who qualified for the September debate will automatically qualify for the October contests, and it gives candidates who did not qualify in September additional time to make the next debate stage.

Candidates need to reach 2% in at least four DNC-approved polls and receive campaign contributions from at least 130,00 unique donors, with at least 400 individual donors from 20 states, by August 28 in order to qualify for the third debates. The polling window for the September debate started on June 28.

The third round is currently set for September 12 and 13. The DNC has capped the number of candidates per debate at 10, so if 10 or fewer qualify, just one round will be held on September 12.

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