The pro-rail organization Pacific Resource Partnership spent more than $1 million on polling, advertising and other election activities this year, pouring almost all of that money into the three-way Honolulu mayor’s race.

PRP, an organization supported by the Hawaii Carpenters Union and unionized contractors, filed a report with the Campaign Spending Commission Tuesday showing PRP spent $1.03 million from Jan. 1 to July 27.

Most of that money was spent polling voters, producing commercials, buying advertising and engaging in other campaign activities related to the mayor’s race.

Former Gov. Ben Cayetano is running for mayor, and has promised to stop the Honolulu rail project if he is elected. Cayetano is opposed by incumbent Mayor Peter Carlisle and former city Managing Director Kirk Caldwell, who both support the rail project.

A poll published this week by the Star-Advertiser and Hawaii News Now shows 44 percent of likely voters say they would vote for Cayetano if the election were held today. Carlisle is supported by 27 percent, followed by Caldwell with 25 percent.