The corruption inquiry is laying the groundwork to question former deputy premier Nathalie Normandeau about ministerial meddling in construction contracts.

A longtime provincial bureaucrat said that he knows of about 50 instances in which government cabinet ministers used their discretionary powers in order to meddle in infrastructure contracts.

Yvan Dumont, Engineering Team Leader at Ministry of Municipal Affairs, told the Charbonneau Commission Tuesday that ministers used discretionary powers to change details of contracts already arranged by government administrators, 32 times under Liberal Nathalie Normandeau, as well as other times by Liberals Laurent Lessard and Jean-Marc Fournier as well as the PQ's André Boisclair.

"From the ministers we never received any explanation," said Dumont.

Generally the province pays about half of the cost of an infrastructure project but that could rise much higher if the minister wishes to be more generous.

Dumont said that the province was particularly generous in 2007, 2009 and 2010.

The Auditor General has long warned against abuses that could occur with the discretionary ministerial power and cited it as an issue in 1996.

Subsequent governments continued with the practice nonetheless.

The inquiry cited an instance in which Liberal minister Laurent Lessard hiked its contribution from 66.66 percent to 80 percent to of the costs of a $10.8 million water facility in Grande-Rivière, Gaspé in 2009.

Dumont said that by its very nature, the system encourages overspending. “A municipality that anticipates getting funded at 95 percent will not make much effort to reduce the cost of a project.”

Normandeau fight came to attention of the Charbonneau commission when she authorized construction of a water treatment plan in Boisbriand against the recommendations of her staff.

Investigators from the Inquiry now suggest that Normandeau may have authorized the plant because of intense lobbying and fundraising efforts by the engineering firm that was responsible for the project.

Normandeau is expected to testify soon at the inquiry.

-With a file from The Canadian Press