BOSTON (AP) - U.S. Sen. Scott Brown has collected more than twice the number of signatures needed to secure a spot on the GOP primary ballot in September.

Brown's campaign announced it gathered more than 20,000 signatures.

U.S. Senate candidates in Massachusetts need at least 10,000 certified signatures to get on the ballot. The deadline for collecting the signatures is May 8.

Brown says the swiftness by which the campaign collected the signatures shows he has a strong field organization that could be critical in a close race.

Campaign officials say they're now redirecting their field work to one-on-one voter contact and other get-out-the-vote efforts.

Signatures must be submitted to local election officials to be certified before they are delivered to the Secretary of the Commonwealth's office.