Pauline Marois says someone who has benefited from collusion is out for revenge against her because of her party's efforts to clean up the system.
The Parti Quebecois leader was responding to damaging allegations released by Radio-Canada, which accuse Marois' husband of accepting $25,000 from an engineering executive.
In Quebec, it is illegal for a company to donate money, and individuals were not allowed to give more than $3,000 during the time in question.
Marois says Radio-Canada's source must be concocting allegations in order to stop her government's fight against corruption.
"This person who is hiding, and was clearly involved in collusion, no doubt wants the Liberals to return," Marois says.
The PQ leader says she does not know who Radio-Canada's source is, but she says it only makes sense that it's someone out for revenge considering that the information was release so close to election day.
"We are denouncing a situation where I have done nothing wrong. Nor my party. Nor my husband," she says.
Radio-Canada says it has other sources corroborating its story.
A second director of an engineering firm told the media outlet that he also gave Claude Blanchet $5,000 during the 2008 election campaign, which was disguised to appear as though the money had come from employees.
As well, two workers listed as donors for Pauline Marois in 2007 also told Radio-Canada that their employer provided them with the funds.