The Crown says Manitoba and BC prosecutors have concluded there are no legal grounds to appeal a jury's not guilty verdict on Mark Stobbe (Stoh-bee).
Stobbe was put on trial for second degree murder in the slaying of Beverly Rowbotham 12 years ago.
Stobbe, who worked for NDP governments in Manitoba and Saskatchewan, has always insisted he had nothing to do with her death.
The jury acquitted him earlier this year after a seven week trial.
The Crown in Manitoba has issued a statement the case could not clear the legal bar to justify an appeal.
"The legal standard for the Crown to bring an appeal is a legal error on a question of law arising during the trial that reasonably could have had a material impact on the decision made by the jury," the statement said.
"The review found that no legal error could be established. Accordingly, an appeal will not be taken of the acquittal of Mr. Stobbe."
Rowbotham's hatchet bludgeoned body was found in her car 15 kilometres away from the couple's home in St. Andrew's, Man., in October, 2000.
Evidence suggested she was killed in her own backyard and her body taken there in the family car.
Stobbe and Rowbotham moved to Manitoba from Saskatchewan when Stobbe took a job as a communications adviser to the then newly elected NDP government of Gary Doer.
Her murder became one of the province's most puzzling unsolved crimes.
The trial heard from 80 witnesses in a case that largely focused on circumstantial evidence.
After the trial Stobbe's lawyer Tim Killeen questioned why the Crown decided to proceed with the trial with so little evidence that did not tie Stobbe in to the killing.