Patrick Mara, the sole Republican seeking the open at-large seat on the D.C. Council, once looked like a shoo-in to appear on the April 26 ballot. After all, he turned in 5,629 petition signatures when a mere 3,000 will do.

But challenges brought by his opponents’ supporters, as well as new questions raised by the D.C. Board of Elections and Ethics, have Mara in very real danger of being jettisoned from the ballot.

Earlier this month, Lawrence Guyot, a supporter of candidate Joshua Lopez, and Bandele McQueen, a supporter of Sekou Biddle, challenged a portion of Mara’s signatures. A review by BOEE staff verified 2,447 of McQueen’s signature challenges, while 302 of Guyot’s stood. Neither challenge by itself is enough to boot Mara, but if combined, it’s possible Mara could drop below 3,000.

Another twist: While reviewing the other challenges, board staff identified about 80 signatures submitted by Mara that are potentially fraudulent. “There were a number of pages that seemed to be written in the same hand,” said BOEE spokeswoman Alysoun McLaughlin. (You can review the pages in question after the jump.)

Again: Eighty discarded signatures wouldn’t be enough to eliminate Mara, but combined with the other challenges, it is entirely possible Mara could sink below 3,000. There is also the possibility that the board could toss all the signatures collected by the circulator responsible for the falsified John Hancocks, multiplying Mara’s problems.

The math is inexact, McLaughlin said, because there is some overlap among the signatures questioned by each party. The BOEE general counsel’s office is currently reviewing each challenge, she said.

At a hearing today, BOEE member Charles Lowery — one of two sitting members of what is supposed to be a three-member board — heard arguments from the various parties. Regarding the alleged forgeries, there is some question over whether the board can question signatures that weren’t challenged by an outside party, but McLaughlin said it is the board’s staff’s “obligation” to raise potential issues.

Lowery must make his ruling by close-of-business Tuesday, and his decision can be reviewed by the D.C. Court of Appeals. If Mara is booted, expect an vigorous appeal. And because the third BOEE seat, reserved for a minority party, is vacant, you can expect some loud debate about the propriety of a Republican being ousted by a board consisting solely of Democrats. (Check Sunday’s Post editorial page for a thorough airing of that issue.)

For now, Mara said he isn’t anticipating that possibility. “I’m just waiting to see how the process plays out,” he said this evening. “I assume that I’ll be on the ballot on April 26.”

For more on today’s proceedings, do check Martin Austermuhle’s excellent Four26 blog, which is exhaustively covering the at-large race.

Here are Mara’s petition pages containing the alleged frauds: