SAN FRANCISCO (AP) _ The government said Wednesday it will retry Larry Layton beginning Jan. 2 on charges of conspiring to murder Rep. Leo Ryan near the Peoples Temple compound in Guyana in 1978.

Even though the jury in the first trial voted 11-1 for acquittal, such serious charges ''should be determined by a jury and not by a prosecutor. ...It's what the people of the United States should expect,'' U.S. Attorney Joseph Russoniello told reporters.

Tony Tamburello, one of Layton's lawyers, later accused Russoniello of ''grandstanding'' and said the retrial was a ''political persecution of the first magnitude.''

Layton, the only former Peoples Temple member to be tried in the United States, is charged with conspiring with the Rev. Jim Jones to kill Ryan and a U.S. diplomat. Ryan and four other people were killed on an airstrip in November 1978, hours before Jones and 912 followers died in their jungle compound.

Layton shot and wounded some temple defectors in one airplane, but witnesses agreed he did not shoot Ryan. However, the prosecution contends a conspiracy among Jones, Layton and others to keep outsiders from learning about conditions at Jonestown led to Ryan's death.

The retrial has been delayed by prosecution attempts to bring in evidence of statements by Jones that were excluded from the first trial.

Chief U.S. District Judge Robert Peckham has agreed to allow some previously excluded evidence, including a tape-recorded statement made by Jones a few days before the shootings telling his followers that Ryan might not leave alive.

But Peckham repeated his earlier refusal to allow into evidence the ''last hour'' tape, in which babies can be heard crying while Jones exhorts his followers to drink poison. The 9th U.S. Circuit Court of Appeals upheld that ruling July 29, and Russoniello said the Justice Department had decided not to appeal.

Layton, who is free on bail and working in an undisclosed job in an east San Francisco Bay community, attended Wednesday's hearing before Peckham.

The judge set the trial date despite complaints from defense lawyers that it will be difficult and time-consuming to locate witnesses in Guyana.

Federal Public Defender James Hewitt said the pilot of an airplane at the airstrip refused to talk to the defense without the consent of the attorney general of Guyana, which was not forthcoming. He said other potential witnesses had left the country.