In what remains one of the tightest congressional races in the country, Republican candidate Martha McSally's legal team is taking steps to toss out the ballots of voters in Pima County.

McSally now leads Democratic Congressman Ron Barber in the Congressional District 2 race by 509 votes, with an estimated 9,000 provisional ballots still left to count. It's unclear how many of those votes are in Congressional District 2.

Attorney Eric H. Spencer, representing McSally and the Republican Party, emailed County Recorder F. Ann Rodriguez this morning to demand that any provisional ballot form that was missing a signature from both a poll worker and a voter be set aside.

Rodriguez and Chris Roads, Pima County registrar of voters, said they would continue processing the provisional ballots.

“Martha McSally will do anything to stop Southern Arizonans from making their voice heard at the ballot box,” said Team Barber spokeswoman Ashley Nash-Hahn. “We’ve seen her tricks before, when she tried to throw out votes in Cochise County, and we aren’t surprised to see her desperate moves to silence the voters of Southern Arizona.”

McSally spokesman Patrick Ptak was not available for comment.

Team McSally took legal action to toss ballots from Latino precincts in her narrow 2012 loss.

In 2012, Barber won the provisional ballot count, capturing roughly 55 percent to McSally's 45 percent.

Here's Spencer's first email:

Ms. Rodriguez and Mr. Nelson,

The Republican Party/McSally for Congress campaign (collectively “the campaign”) formally challenges the validity of all provisional ballots that have a provisional ballot form with a missing election official signature.

Page 152 of the Secretary of State’s Election Procedures Manual states that, prior to voting a provisional ballot: “An election official or voter completes a provisional ballot form. The voter and the election official sign the provisional ballot form.”

After voting the ballot, “[t]he voter will return the sealed envelope to the election official, who will verify the envelope is properly filled out, signed and sealed.” Id.

Accordingly, the campaign respectfully requests the following immediate relief:

· The recorder’s office instruct staff to not verify any provisional ballots with a missing election official signature on the provisional ballot form;

· The recorder’s office cease transmitting any previously-verified provisional ballots to the elections department, pending a review of the provisional ballot forms for missing election official signatures;

· The elections department cease processing any provisional ballots or transmitting any provisional ballots for counting, pending a review of the provisional ballot forms for missing election official signatures; and

· The recorder’s office and elections department collect and embargo any provisional ballots that contain a provisional ballot form with missing election official signatures, pending a final legal review and determination in conjunction with the County Attorney’s office.

Given the exigency of this matter, please confirm by 10:15 a.m. that the recorder’s office and elections department will immediately implement these prophylactic procedures.

Here is the response from Roads.

Mr. Spencer,

In response to your challenge, the Pima County Recorder’s Office will not stop processing the provisional ballots. Whether or not the poll worker signed the provisional is clearly identifiable from a simple examination of the provisional ballot form whether or not the provisional is processed by the Recorder’s Office. Therefore our processing has no bearing as to your challenge. In other words, the fact that we processed the provisional form will not impact your ability to proceed with your challenge. The Recorder’s Office is under a statutory deadline to complete processing the provisional ballots and we will continue to proceed toward meeting that deadline.

Please note that your extremely short deadlines for responses are unreasonable. Under Arizona law we have a reasonable time to respond to public records requests and other matters. A deadline of less than 30 minutes is far less than reasonable.

Both candidates have attorneys on site in our office observing our processes and tracking the work we are doing.