Bennett, a member of the Movement for Democratic Change and close ally of Prime Minister Morgan Tsvangirai, faces a possible death sentence if convicted of illegal possession of arms for purposes of committing terrorism, sabotage and banditry.
"The entire state's case is based on fiction," Bennett's lawyer, Beatrice Mtetwa, told the court. "We submit that the facts presented by the state are not sufficient to have a conviction."
The prosecution's case -- that Bennett planned to fund a 2006 plot to blow up a major communications link and assassinate key government officials -- hinges on emails that prosecutors say link the former commercial farmer to the crime.
Mtetwa has said the e-mails could have been created by anyone to implicate Bennett.
The state's case was dealt a blow last month when its chief witness -- former policeman and arms dealer Peter Hitschmann -- disowned the emails and denied Bennett was involved.
Bennett claimed that he is being persecuted by President Robert Mugabe's ZANU-PF party to stop him from taking up the post of deputy agriculture minister.
State prosecutors Thursday are expected to ask the court to reject the defense's application to drop the case and, instead, ask Bennett to take the stand.
