"The Bennett trial… is expected to start today at 10:00 (12:00 GMT)," his lawyer Beatrice Mtetwa said.
"However, before the trial starts there are some preliminary issues we want to raise as we feel these are out of order and they are hear say," she said.
Mtetwa said she was concerned that one of the key state witnesses testified differently from "what is already contained in his witness account".
Bennett was first arrested in February on his return from South Africa to take up the post of deputy agriculture minister in the unity government.
Instead of being sworn in with other cabinet members, he was accused of possessing arms for the purposes of banditry, terrorism and sabotage.
Since his arrest, he has been in and out of prison, prompting Tsvangirai’s decision to boycott the unity government three weeks ago.
The stand-off ended last Thursday, following an intervention by regional leaders.
The matter would be heard by Judge Chinembiri Bhunu.