The city on Thursday will suspend its controversial ad campaign for its planned $3.7 billion rail transit system.

The city spent nearly $2.6 million from August 2005 through June 30, 2008, on a rapid-transit public information campaign that includes pro-rail advertising, community meetings and speakers bureau presentations, a monthly newsletter and a project Web site and hot line.

More than $1 million of that money was spent since February 2008. That figure excludes about $176,000, which was spent on a new brochure that was inserted into last weekend's Honolulu newspapers.

Some of those public outreach efforts are mandated by the federal government, which is expected to pay for a portion of the mass transit system. However, citizens group Stop Rail Now contends the city is using taxpayer money to sway public opinion in favor of rail in advance of a Nov. 4 vote that's key to the project's future.

City attorneys maintain the pro-rail ad effort is legal so long as the ads don't explicitly tell residents to vote for rail, or exaggerate the impacts of a vote for or against the project. However, that public relations effort has drawn the ire of rail opponents who have only a fraction of the resources to counter a city-sponsored campaign.

Yesterday, Stop Rail Now sent a letter to Honolulu Mayor Mufi Hannemann requesting the city give anti-rail groups equal time and space to provide the public with information against rail.

"We're not claiming it's illegal," said Stop Rail Now co-founder Dennis Callan. "We're claiming it's unethical and dishonest and a misuse of taxpayer money.

"The bottom line is there should be balanced information particularly with the ballot issue."

Groups for and against the rail project are focusing on winning public opinion on the rail transit issue prior to the Nov. 4 vote on a City Charter amendment authorizing the construction of a train. The city contends the amount of money spent on public information represents about 2 percent of the total value of transit project contracts given to date. Funding for the contracts is included in the City Council-approved budgets, according to an e-mail from city spokesman Bill Brennan.

Brennan said he had not seen the Stop Rail Now letter. However, he said the city has no plans to buy ads after Thursday, which is the last scheduled community meeting for the rail project prior to the Nov. 4 vote.

Hannemann hopes to break ground on the commuter rail late next year, with the first East Kapolei to Leeward Community College segment opening in 2012. The transit system is expected to reduce urban sprawl while giving commuters an alternative to increasingly congested highways.

Critics contend the project is too costly and won't prevent traffic from worsening along the busy H-1 Freeway.

Among those in favor of rail are labor unions, land developers, the city, Hannemann and groups such as www.gorailgo.org. On the other side are grassroots groups such as Stop Rail Now, www.honolulutraffic.com and www.therailscam.com.

So far, pro-rail groups are outspending anti-rail groups.

The Hawaii Carpenters Union, which has 5,900 members, spent more than $50,531 last month to convince residents to vote for rail, according to filings with the Hawai'i Campaign Spending Commission. That exceeded the $43,400 spent by Stop Rail Now and one other anti-rail group. Stop Rail Now backer Cliff Slater yesterday said the group hopes to spend about $100,000 advocating against rail prior to the November vote.

The Hawaii Carpenters Union yesterday said it will increase the frequency of its pro-rail ads in the remaining two weeks before the rail vote. The group would not disclose how much it is spending on the ads.

The Hawaii Carpenters Union is joined by the Pacific Resource Partnership, which also is purchasing pro-rail radio ads. The partnership is a joint program of the Hawaii Carpenters Union, Local 745, and its 220 signatory contractors across the state.

Separately, Hannemann's re-election campaign also has purchased pro-rail ads.