FORT COLLINS, Colo.  The parents accused of concocting a publicity stunt by pretending their young son had climbed aboard a homemade helium balloon and was hurtling through the Colorado skies will surrender to the authorities as soon as charges are filed, the lawyer for the father said Monday.

David Lane, a Colorado civil rights and defense lawyer who is representing the father, Richard Heene, said both Mr. Heene and his wife, Mayumi, would plead not guilty and would turn themselves in to avoid further public spectacle. Mr. Lane contended that placing handcuffs on the Heenes, in the full glare of the news media and for their children to see, would be abusive to the youngsters.

The case became a national sensation last Thursday, when the Heenes frantically reported that their 6-year-old son, Falcon, had climbed into the silver flying saucer his father built in their backyard here and had drifted into the sky, prompting a wide-scale search. The child was later said to have been home the whole time.

The Heenes, who had appeared on the show “Wife Swap,” have made no secret of their television aspirations. At a news conference on Sunday, the Larimer County sheriff, Jim Alderden, said the entire series of events had been an elaborate hoax drummed up by the Heenes to gain attention and leverage for a reality TV show.