The legislation follows a request by inquiry chairwoman France Charbonneau for more independence in the gathering of evidence.
The bill would allow the commission to obtain documents without needing a subpoena and give it increased power to inspect documents.
"We have given commissioner Charbonneau an important mandate and we have complete confidence in her,'' Fournier said.
"We believe these additional tools will allow the commission to conduct its inquiry as best it can, which can only contribute to the rigour and thoroughness of its recommendations."
Charbonneau, a Quebec Superior Court justice and a former prosecutor known for convicting Hells Angels kingpin Maurice (Mom) Boucher, is to give the opening remarks on May 22.
Witnesses will be heard later in the year,
Premier Jean Charest called the inquiry in February after tremendous public pressure.
Charest spent two years resisting demands for an inquiry despite mounting evidence that criminal collusion involving organized crime groups like the Mafia drove up the cost of public-works contracts in Quebec.
There have also been allegations of corrupt money switching from the same criminals to the coffers of political parties.