A group of activist lawyers say four Northern California protesters on trial in Sacramento are being denied basic constitutional rights.

The National Lawyers Guild chapter in Sacramento is representing the protesters, who are known as the "Wheatland 4."

Spokesman Cres Vellucci says the four are facing fines and up to six months in federal prison if convicted, but the courts are refusing to allow a jury trial.

"The government has used a little loophole in the law that means that they have no right to a trial of their peers," Vellucci said. 

The protestors are charged with trespassing for trying to deliver a protest letter over so-called "killer drones" to the commander at Beale Air Force Base.

Vellucci says an appeal will be filed if there's a guilty verdict.