MONTREAL -- Former Quebec deputy premier Nathalie Normandeau told the provincial corruption inquiry Wednesday that if questionable activities were going on in her office, it was happening without her knowledge.

Normandeau put the blame on corrupt engineering firms.

The ex-provincial politician used her long-awaited one day appearance at the Charbonneau Commission to defend the decisions she took while serving as a cabinet minister and sought to set the record straight about allegations of influence peddling levelled against her.

Normandeau told the Charbonneau Commission she exercised her discretionary powers as a cabinet minister with care and insisted she didn't put undue pressure on civil servants.

Normandeau's name has been mentioned frequently during testimony at the Charbonneau Commission and she's been accused of benefiting from illegal financing practices, accepting gifts from entrepreneurs and favouring funding for projects involving firms that donated heavily to the Quebec Liberal party.

Normandeau has denied any wrongdoing and repeated that again on Wednesday. She welcomed the opportunity to clear the air after two years of allegations.

She defended intervening in certain files, saying that discretionary powers are an important tool for a cabinet minister.

As municipal affairs minister, she was charged with overseeing which municipalities got subsidies for projects. The towns themselves awarded the contracts.

Normandeau said that discretionary power exists to counterbalance the power of civil servants.

She estimated she increased the subsidies on 32 of 708 files that crossed her desk because she didn't believe the funding was adequate. And sending files back to department officials was not a form of pressure, she added.

"That's 4.5 per cent of files where I used my discretionary power," Normandeau said. "I don't call that pressure. I call that doing my job as minister."

Normandeau was also asked about Bruno Lortie, her former chief of staff, who was on the stand Tuesday. She initially defended the senior member of her staff, calling him a diligent person who she had no reason to doubt during the eight years they worked together.

Lortie had close ties with Roche engineering executive Marc-Yvan Cote, once a former Liberal member of the legislature himself. Lortie described him as being like family with Cote and he'd often push for files involving Roche as a result.

Through Cote, Roche was involved in organizing fundraising events for the party and donated heavily too.

Normandeau said all parties were asking businesses and engineering firms for money, but the strawman system employed by those firms was problematic.

"I sincerely believe that the strawman system basically perverted a system that was noble," she said.

The so-called strawman system allowed companies to use third parties to pose as donors and reimbursed them after the fact. It allowed for companies to get around stringent Quebec donating rules that have since been tightened further.

Other witnesses testified that Lortie would often interfere in the handing out of subsidies and was closely involved. On the stand, Lortie had trouble remembering many of the details.

Initially, Normandeau repeated that she trusted Lortie, who served with her for her entire time in cabinet. But later, she agreed the allegations against Lortie were troubling.

"If Mr. Lortie gave inside information to Roche, it's reprehensible and inexcusable," Normandeau said. "You can't do that."

Normandeau said she would have fired Lortie if she'd had any inkling he was doing anything wrong, but cautioned the allegations against Lortie remain unproven.

"I hope he didn't betray my trust," Normandeau added.

The former Liberal cabinet minister is the highest-ranking politician to take the stand at the probe. She spent five years in opposition before becoming Tourism Minister in 2003 under then-premier Jean Charest's Liberal government.

She became municipal affairs minister in 2005 and quit politics suddenly in 2011.

Normandeau said Wednesday that it was Charest himself that plucked her from her mayor's chair in her hometown of Maria, in the Gaspe region.

Normandeau has been on the defensive over the past several months amid swirling allegations.

Her name has also surfaced at the inquiry in 2012 following allegations that she received gifts like Celine Dion concert tickets and roses from controversial construction boss Lino Zambito.

On that issue, Normandeau said that she didn't know Zambito and had only met him on four occaisons, including the concert. The concert tickets were given to her through Lortie and she now has regrets having gone to the event.

"I didn't have any relationship with Mr. Zambito," she said.

This year, anti-corruption police officials have alleged in warrant documents that she intervened in favour of the Roche engineering firm against the advice of civil servants.

However, no charges have been laid and the allegations have not been tested in court.

Normandeau has insisted she was not influenced by the gifts and was not involved illegal fundraising. She said she took care to keep an arm's length between her ministerial role and her role in the party itself.

"I always erected a wall between my office and my role as a party member, and believe me, I was not naive enough to believe that some people who were there (at the fundraisers) did not think, perhaps, they'd get something in return for their involvement in the Quebec Liberal Party," said Normandeau.

"But those people were wrong because there was never any return."

In her testimony, she pinned the blame on engineering firms and said she was revolted by what she's heard at the inquiry about false invoicing, strawmen schemes to circumvent fundraising rules and influencing civil servants with gifts and perks.

She adds her hope is that UPAC, the province's anti-corruption police unit, gets to the bottom of it.

"I hope that UPAC's investigations will yield results," she said.

Normandeau offered a number of recommendations at the end of her testimony, calling for a culture of transparency in government.

She said the political class can improve on what exists with stricter lobbying laws and better transparency when it comes to public contracts.

A new witness is expected on Thursday.