Two South Florida Muslim clerics — a father and son separated by more than 50 years in age — are struggling to persuade a Miami federal judge to allow their lawyers to travel to Pakistan to question alleged Taliban sympathizers who might help their defense against terrorism charges.

Lawyers for Hafiz Khan and Izhar Khan, former imams of mosques in Miami and Margate, have already lost their first bid to travel with federal prosecutors to the U.S. Embassy in Islamabad to take depositions from five witnesses who do not want to come to Miami to testify at the upcoming trial.

Among the potential witnesses are two other Khan family members and another suspected Taliban supporter who were accused in the same case of conspiring to aid the Taliban with money and guns.

Last week, U.S. District Judge Robert Scola rejected the defense’s initial deposition plan — which was strongly opposed by federal prosecutors — as “unsafe and impractical.” But Scola left open the possibility for the defense’s alternative: allowing the Khans’ lawyers to question the witnesses at a hotel such as the Marriott in Islamabad in a live, videotaped deposition with the prosecutors participating from Miami.

“If there is a way for you to take their deposition, I’m going to let you do it,” Scola said, setting the stage for a final hearing Oct. 29.

The clock is ticking, however, because the “material-support” trial that initially drew national headlines is scheduled for early January. Bottom line, the defense said: No deposition, no fair trial.

“These witnesses are so important if we’re going to have any defense,” Izhar Khan’s lawyer, Joseph Rosenbaum, told the judge. “Without [the deposition], we don’t have a shot.”

Rosenbaum argued that that the prosecutors oppose any deposition of the Pakistani witnesses because their testimony could poke holes in the government’s case, which is built on phone recordings of the Khan family’s alleged network of fundraising for the Taliban, a U.S.-designated terrorist group.

He further argued that witnesses would provide “context” for the phone calls, proving that the defendants wired about $50,000 from Miami to Pakistan to aid schools and families in the embattled northwest territory known as the Swat Valley — not to fund the Taliban’s violence against the U.S. government interests in the region.

Assistant U.S. Attorneys Pat Sullivan and John Shipley said in court they were opposed to any deposition, even if it were taken at a modern hotel in Islamabad. They declined to say why at Thursday’s hearing.

In court documents, they opposed the defense’s initial deposition plan, saying Pakistan is dangerous and that the witnesses could not be questioned at the U.S. Embassy because of their involvement in the alleged crime of aiding the Taliban. A fourth witness for the defense, Noor Mohammed, is suspected of being a Taliban soldier, and a fifth is a Pakistani pharmacist who received some of the money transfers from Hafiz Khan’s foreign bank accounts.

On Thursday, the prosecutors called an FBI witness who served at the U.S. Embassy in Islamabad over the past year to testify about the safety risks of taking the deposition there as well as outside the diplomatic zone.