Lawyers for a man charged with providing support to al-Qaida asked a judge Wednesday to postpone the start of his trial, saying they feel "sandbagged" by prosecutors.

Tarek Mehanna of Sudbury is accused in an indictment of conspiring to kill American troops in Iraq. His trial is scheduled to begin Oct. 3.

During a court hearing Wednesday, Mehanna's lawyers said prosecutors had promised to turn over evidence but hadn't done so in time for them to get ready for trial. Janice Bassil said prosecutors gave the defense nearly 17,000 pages on Tuesday, some of it in Arabic.

"At this point, we're not going to be ready (for trial)," Bassil said.

J.W. Carney Jr., another of Mehanna's lawyers, said prosecutors have repeatedly assured them over the last several months that they would give the defense a list of exhibits and witnesses but still haven't provided the information.

"I feel we've been sandbagged," Carney said.

Assistant U.S. Attorney Aloke Chakravarty said prosecutors have consistently given the defense evidence throughout the case. He said the government had recently given the defense material it had already turned over, but this time in a different, more usable form.

"As we've gone though and identified evidence, we've given it to them," he said.

Chakravarty said he resented Carney's accusation that prosecutors had rescinded on their promise to turn over evidence.

"The government promised to do what it is doing," he said.

U.S. District Judge George O'Toole Jr. didn't immediately rule on the request to delay the start of the trial. He scheduled another hearing for Sept. 15.

Prosecutors say Mehanna made an unsuccessful trip to Yemen to seek training in a terrorist camp and translated a publication entitled "39 Ways to Serve and Participate in Jihad," Muslim holy war.

He was initially charged with lying to the FBI in 2008, but the more serious terror-related charges were added in 2009.

Authorities have said Mehanna and two other men told friends they were rejected for terrorist training because of their nationality, ethnicity or inexperience, or that they were unable to make contact with people they hoped would get them into such camps.

Mehanna's lawyers say his activities amounted to free speech protected by the First Amendment.

About 30 of Mehanna's supporters attended the court hearing wearing yellow fleece scarves as a sign of solidarity.