More than 600,000 mail-in ballots requested for Massachusetts primaries

BOSTON - Hundreds of thousands of voters in Massachusetts have requested mail-in ballots ahead of the Sept. 6 primaries.

A spokeswoman for the secretary of state's office says that as of Tuesday morning, they had received 637,744 requests for mail-in ballots. A total of 621,473 ballots have been mailed out in response.

Just under 30% (185,594) of those ballots have already been returned.

Election officials are urging voters who requested a mail-in ballot to fill them out and send them back as soon as possible. 

Postal service delivery can take up to seven days, and all ballots must be received by 8 p.m. on September 6 to count.

Anyone who hasn't already applied to receive a mail-in ballot can fill out an application online through August 29.