Rick Manter, a former colleague of the mayor's at the public relations and lobbying firm of NCG Porter Novelli.

Word on the street has it that the current effort by labor unions and downtown hotels to qualify a tourist tax measure for the November ballot has hit a funding wall, with a paltry $630,531 collected by backers through this week, according to city disclosure records.

San Diego Convention Center. Pro-convention center expansion forces could be forced to return to the city council.

Of those funds, just $136,585 was paid to Arno Petition Consultants of Gold River, California, filings show, a mere pittance in the big money game of buying one's way onto the ballot. At the end of March, Arno was owed $37,653, per the report, covering the first three months of the year.

By comparison, in 2016 Arno got a total of $1.9 million during the two months from April 18 through June 15, gathering signatures for the ultimately ill-fated Chargers stadium. Similarly, during last year's successful bid to get the controversial SoccerCity Mission Valley privatization deal on the ballot for voter consideration, sponsors spent a total of $836,838 for Arno's signature-gathering.

SoccerCity's rival, Friends of SDSU, which subsequently mounted a competing ballot measure to pick off the city-owned land currently occupied by the former Qualcomm Stadium, spent $1.2 million last fall for the petition services of AAP Holding Company, Inc, of Westlake Village, filings show.

Thus, facing the prospect of insufficient funds to pay Arno’s price, the pro-convention center expansion forces could be forced to return to the city council to get some version of their measure onto the ballot, insiders note.

Though Democrats rejected an expansion plan tax measure backed by Republican mayor Kevin Faulconer last June on a 5-4 vote, co-sponsorship of the current initiative effort by labor unions could favorably alter the odds of success.

But certain to raise questions among some Democrats is the role with the pro-expansion group of longtime Faulconer friend and close confident Rick Manter, a former colleague of the mayor's at the public relations and lobbying firm of NCG Porter Novelli. Manter Communications of Tustin received $17,888 and was owed travel expenses of $18,551, according to the convention center committee's April 30 report, covering the first three months of 2018.

Over the past four years, records show, Manter’s firm has gotten a total of $246,362 from city campaigns, including $140,979 from 2014's successful referendum effort to beat back the Barrio Logan community plan.

Manter also made $49,671 on 2014's Faulconer-backed signature drive that put the city council-adopted minimum wage ordinance on the ballot. Though subsequently approved by voters, its effect was delayed more than a year.