A former Quebec deputy premier is among seven people arrested in an alleged scheme in which political financing and gifts were said to be exchanged for lucrative government contracts.

Ex-Liberal cabinet minister Nathalie Normandeau was among those arrested Thursday in early morning sweeps by the province's anti-corruption unit, known as UPAC.

Also facing charges are: Marc-Yvan Cote, former Bourassa-era Liberal cabinet minister; Bruno Lortie, Normandeau's former chief of staff; Mario W. Martel and France Michaud, two former executives with engineering firm Roche; Ernest Murray, a former political aide to ex-PQ leader Pauline Marois; and Francois Roussy, the former mayor of Gaspe.

According to charges filed in Quebec Court, the accused are facing charges that include corruption, fraud towards the government, conspiracy, breach of trust, and using forged documents — acts alleged to have occurred between 2000 and 2012.

All of the accused are to appear in court in Quebec City on April 20th.

"It is unfair and unequal to use political contracts as a political tool," anti-corruption unit chief Robert Lafreniere told a news conference. "And it's also unacceptable to use the power of influence to favour elections."

Authorities say the "marathon" investigation started out as two distinct investigations but were merged into one.

"Among the accused, we have on one hand, people from the political class, both on the provincial and municipal levels," said Andre Boulanger, head of investigations for the anti-corruption unit. "And on the other hand, we have influential administrators from the engineering firm Roche."

Boulanger said that at different times and in different ways laws were circumvented to gain unfair advantages such as gifts, party financing and for some, public contracts.

Normandeau worked for Quebec City radio station FM93. It reported this morning that she had been arrested and later announced she was suspended without pay.

She testified in 2014 at the Charbonneau Commission, which looked into corruption in the construction industry, as did many of the others arrested on Thursday.

Word of the arrests created a stir in Quebec City, where the provincial budget is to be released later Thursday.

Premier Philippe Couillard said political financing in the province has changed in recent years and doesn't reflect the party he leads today.

"We should all be collectively very happy that we've completely changed the landscape and the environment," Couillard said.

The changes included capping donations to $100 per person per year. Couillard adds the party brought in internal protocols to deal with raising money.

"The ambience is totally different, fundraising is not an issue anymore for us," Couillard added. "We're doing politics, we're talking about ideas, we're talking with our volunteers all across Quebec, and that's the way politics should be done."

Public Security Minister Martin Coiteux said the arrests reflect that the anti-corruption unit's work is completely independent.

"What's important to remember is absolutely no one is above the law," Coiteux said.