PROVIDENCE, R.I. (WPRI) — Democrat Gabe Amo on Thursday released a poll showing him surging to second place in Rhode Island’s Sept. 5 congressional primary, with Aaron Regunberg leading the pack and Sabina Matos falling well behind.

The poll of 451 voters conducted for Amo’s campaign found Regunberg at 28%, Amo at 19%, Matos tied with Sandra Cano at 11% each, and Don Carlson at 8%, with 15% still undecided.

Amo’s team released the full poll results — an unusual move by a major campaign — in an effort to give them credibility with reporters and voters. The survey did not list all 12 Democrats on the ballot in the primary by name, only the five who have had enough resources to run TV ads, with the others lumped in as an option for “another candidate not mentioned here.”

The Amo campaign poll suggests the scandal over forged campaign signatures has done heavy damage to Matos’s image among primary voters. She is now viewed unfavorably by 44% of primary voters, up from 24% in a previous poll they did in June, while her favorable rating has dropped to 24% from 44%.

Matt Rauschenbach, Amo’s spokesperson, argued that “it is clear that Gabe is the only chance at beating Regunberg, and he is well positioned to do so.”

The survey was conducted Aug. 15 to Aug. 17 by Global Strategy Group, the polling firm working for Amo, and was conducted by text message and automatic telephone call.

There has been no independent polling in the primary to date. But Amo’s poll marks the third time one of the candidates has released their internal numbers, giving some sense of the trajectory of the race over the summer.

Back in June, Matos said her internal poll showed her leading the pack with 22% of the vote, well ahead of Regunberg at 9%, with the rest of the candidates in lower single-digits and over 40% of voters undecided.

Then in July, former candidate Nick Autiello released an internal poll his campaign conducted showing Matos on top with 20% of the vote, followed by Regunberg at 12%, Cano at 7% and Amo at 6%.

Both of those surveys were conducted prior to the signature scandal, which rocked the Matos campaign.

An earlier version of this report said Matos and Cano were tied with 10% in the Amo poll; they were tied with 11% in the poll.