Midtown vendors, alarmed they may be ordered to vacate their stalls for the month preceding the Republican National Convention, are joining forces to demand information.

“The rumor is they’re going to close the area for a month, but there is nothing official,” Alipio Castillo, who sells grilled meat on the corner of 31st Street and Eighth Avenue, said in Spanish. “We want to know in order to be prepared. I don’t live from a salary and if they close really early I don’t have a way to live.”

Mr. Castillo, a 52-year-old Peruvian immigrant who said he has worked on that corner for 15 years, will be one speaker demanding details about vending closures during the convention at a demonstration tomorrow morning organized by the newly formed Madison Square Garden Street Vendors Association.

Mayor Bloomberg and Police Commissioner Raymond Kelly announced detailed traffic plans for the convention nearly a month ago, but have not yet said if vendors would have to vacate the area.

A spokesman for the Police Department, Michael Coan, said yesterday most of the area between 31st and 34th streets and between Sixth and Ninth avenues would be closed to vendors for up to a week during the convention. He said the vendors had not been informed of the plan.

“They will be notified within the next couple of weeks,” he said, adding that fliers, merchant associations, and the Department of Consumer Affairs would be used to spread the word.

Sean Basinki, an organizer with the Street Vendors Project at the Urban Justice Center, said his group sent a June 7 letter to the police department and has made repeated phone calls, with no response. When that failed they worked with area vendors to form the association on July 1.

“The purpose is to bring to light the fact that the city has not yet responded to questions about what will be done during the convention and after to the vendors,” Mr. Basinski, who estimates more than a hundred vendors work in the affected area, said of tomorrow’s demonstration.

The association had its last meeting Thursday at Dunkin’ Donuts on 32nd Street, where about a half-dozen vendors of as many nationalities came together to raise their concerns. After a full day of work, the vendors remained for two hours engaged in discussion of rumors heard and how to respond.

“My concern is they’re going to move us off the block in the end of August, prime chunk of time in the summer season with the tourists,” Laronz Murray, who sells poetry and artwork on 34th Street and 7th Avenue, said after the meeting. “At Christmas season [the police] come around the 10th of December, they get us off the blocks. The captain says start closing down the streets because of complaints there are too many vendors.”

“We just want to know when they want to close this area,” said Sikdar Khair, another grilled meat vendor on 31st Street. Mr. Khair said he found out from a post office worker his business would be shut down. “I want to know if they’re going to close only four days – if they close more than that I’m going to hurt.”

The nascent vendors association could take as an example the convention-area’s homeless advocates, who appear to have successfully mobilized a positive response from the city.

After the advocacy group Picture the Homeless did not receive a reply to a letter sent to Mr. Kelly in January, members began to organize “operation cardboard box,” bringing together service providers, the Department of Homeless Services, and police officers, to ensure the area’s homeless would not suffer as a result of the convention, said Lynn Lewis, a director of the group.

“Where as you or I might just say, ugh, I’m just going to stay home,” Ms. Lewis said, “if you’re homeless you’re moving throughout the area and that’s where we see the danger to folks.”

Ms. Lewis said in addition to 1,300 people who eat lunch at the largest soup kitchen in the city, Holy Apostle, there are scores of public assistance sites such as shelters, drug clinics, and homeless youth centers within the restricted area.