HONOLULU -- Organizers of a campaign to stop Oahu's planned rail transit project say they have about one-third the signatures needed to put the question to the voters this fall, but face a critical deadline.

The Stop Rail Now organization opened its campaign headquarters on Monday.

The group has a little more than two months to gather another 20,000 signatures needed to force a referendum on rail this fall.

Stop Rail Now volunteers took their message to the few people driving downtown at midday on the Memorial Day holiday. Upstairs they opened a small headquarters, where volunteers prepared petitions.

Dr. Michael Uechi has collected 900 signatures from patients and staff of his urology practice.

"My patients are very akamai. They understand the reasons we're doing this, and all of them are just coming out and signing on," Uechi said.

Stop Rail Now organizers say they've collected about 10,300 signatures in the last month.

"So, we're off to a good start. We have a long way to go yet. Our goal is 40,000 and we've got two more months to go," Stop Rail Now Co-Chairman Dennis Callan said.

The group must turn in 30,000 signatures by Aug. 5 to get the anti-rail petition on the ballot, but it wants 40,000 overall because some folks will have illegible handwriting or be disqualified. So, group members want a buffer.

"We're knocking on doors -- getting signatures. We're dropping petitions off for people to sign and mail back to us. So, this is a major new expansion of our campaign," Callan said.

The group relies on volunteers. It reports it raised $6,000 to $7,000 so far.

"Which is enough for basic materials, nothing like the city's expenditure of millions of dollars for publicity, which we feel is unfair and perhaps even illegal," Callan said.

The group says 200 active volunteers are working in Stop Rail Now.

Even though the city has already spent more than $100 million on rail transit, opponents said it is still better to cancel the project now and build cheaper alternatives like toll lanes than to spend more than $4 billion on a rail system.