BOULDER - Municipalization supporters have closed the spending gap with Xcel Energy Inc. in this year's election compared with 2011. But those same supporters are wary that the competitiveness is a mirage.

The two main issue committees in support of the city of Boulder creating a municipal electric utility - Empower our Future and Voters Against Xcel Buying Elections - have raised $283,510 to oppose Issue 310, which would require voter approval for any debt issued by the city in relation to a municipal utility.

That's compared to the $300,000 lump sum Xcel donated last month to Voter Approval of Debt Limits, the committee responsible for getting Issue 310 on the ballot. In all, Voter Approval of Debt Limits has raised $322,100.

The numbers are from filings made with the city as of Tuesday.

"It's still a fraction of what is probably going to be spent on the other side between now and election day," said Steve Fenberg, executive director of New Era Colorado, which created Voters Against Xcel Buying Elections. "I expect (Xcel) to spend much more."

Xcel spent nearly $1 million in 2011 to fight a ballot measure that voters narrowly approved, granting city leaders the right to pursue creating a municipal utility. Municipalization supporters raised a little more than $100,000 in that campaign.

Xcel spokeswoman Michelle Aguayo said Thursday that she didn't know what if any further contributions are planned as Nov. 5 nears. In addition to the $300,000 donation to Voter Approval of Debt Limits, Xcel has spent $29,106 on wages for employees and lawyers working on the campaign.

"There could be more contributions coming, but as always we'll file that as needed," Aguayo said.

Voter Approval of Debt Limits has spent $303,980 of the money it has raised, and spokeswoman Katy Atkinson said she was unsure whether more money was coming the group's way from Xcel. Issue committees have to file new contributions and expenditures with the city of Boulder each Tuesday. Voter Approval of Debt Limits reported no new contributions or expenditures in the past week.

Voters began receiving ballots in the mail this week.

"What we're up to is very much the basics, getting our message out there via television and direct mail, primarily," Atkinson said of the campaign's stretch run. "We're identifying our voters and getting into voter turnout mode."

New Era's issue committee filing shows it has raised $205,657.47, although a $25,000 donation from the Sierra Club was mistakenly left off the report. So its actual total, Fenberg said, is $230,657.47. New Era raised nearly $181,000 through an online crowdfunding campaign that drew money from all over the nation.

The organization has spent only about $105,000, including staff wages. Fenberg said the plan is to do more of what it's been doing, talking to voters in person and running print and television ads.

Empower Our Future, another issue committee fighting 310, has raised $52,852, and committee chairman Ken Regelson said all of that money either has been spent or budgeted for television ads, print ads, direct mailings and other campaign literature.

Outside of individual contributions, Regelson said, his group doesn't expect any more major contributions.

The municipalization debate has been polarizing, to say the least. The city has placed measure 2E on the ballot to compete with 310. The city-initiated measure would limit only the amount Boulder could pay in the acquisition of Xcel assets and stranded costs owed to the company.

In addition to requiring voter approval for any debt issued by a municipal utility, 310 would limit such elections to odd-numbered years and require that customers of the utility who live outside city boundaries be allowed to vote on those matters. Those requirements, municipalization proponents have said, would essentially kill municipalization and any bargaining power the city might have in pushing Xcel to more rapidly shift its energy mix to renewable sources if the city were to keep Xcel as its service provider.

Hundreds of individuals have donated to the two pro-muni committees. While the amounts have been relatively small, five city council members, including Mayor Matt Appelbaum, Macon Cowles, KC Becker, Lisa Morzel and Suzanne Jones, have donated to those causes. Namaste Solar, meanwhile, has been in the pro-muni corner from a business standpoint.

Outside of Xcel, Voter Approval of Debt Limits financial supporters have been few in number, although not necessarily in stature. Boulder venture capital firm Foundry Group donated $5,000 to VADL over the summer as it worked to gather enough signatures to place 310 on the ballot, while a prominent real estate development company, Tebo Development Co., gave $1,500 during the same time frame.