A report on federal spending in the 1995 referendum campaign could drop another political bomb this week in the camp of Liberal Premier Jean Charest.

A judge is set to release a report Tuesday into Option Canada, an organization alleged to have secretly channeled almost $5 million in federal cash to help the No campaign, contrary to Quebec election laws. The No side won the referendum by a small margin.

The long-awaited report by retired Quebec court Judge Bernard Grenier is expected to lay blame with a number of people who testified before him, including key provincial Liberals. Grenier's witnesses have been kept under tight wraps and have testified in private, including Charest in late April.

"So far, we don't know the names of who has been cited in the report," said political scientist Guy Lachapelle, a failed Parti Québécois candidate in the last provincial election. "The names of people that will come out will be very critical."

Grenier's report likely won't touch Charest directly, who was a federal politician and vice-president of the No Commitee at the time. But it could certainly raise questions about some of his closest associates and the credibility of Liberal Party of Quebec, Lachapelle said.

The report comes as Charest faces the prospect of his minority government falling apart. He is locked in a standoff with opposition parties that have vowed to vote against  the Liberal government's budget and proposed $950-million tax cut.

"Beyond the budget, it will give the [PQ] the opportunity to get off the question of only the budget and call the election on something else that might be perceived as a question of integrity in the people who govern," said Lachapelle, a Concordia University professor.

According to Quebec electoral rules, each side in the referendum campaign was limited to a $5 million spending budget.

The allegations are that Option Canada, a Montreal-based lobby group, doubled the No side's budget for advertising and polls.

The report's impact could even reach Bay Street, since big business was so heavily involved in Option Canada during its brief existence.

"Everyone in Option Canada was so close to corporate people in Toronto, they will be touched in some way," Lachapelle said.

Some of the witnesses at Grenier's hearings have close links to both Charest and the Quebec Liberals.

Alfred Pilon, Charest's former chief of staff, and Claude Dauphin, an aide to then federal finance minister Paul Martin, were key players in Option Canada. Dauphin has since moved on to Montreal municipal politics.

Option Canada was created by the Council for Canadian Unity just eight weeks before the referendum. The council's head was Jocelyn Beaudoin, later named by the Charest government as Quebec's representative in Toronto.

He agreed to a paid leave of absence following the publication of a book into the scandal.

Political scientist Jean Crete said it will all come down to what's in the report and who is blamed. The professor at Laval University in Quebec City said that if a civil servant is blamed, it won't make a huge difference.

"If it is elected people who are blamed, it'll be different," Crete said. "If there's nothing in the report, it will do nothing. The main thing in Quebec is the budget, because it is the difference between being the government or not."

Marcel Blanchet, Quebec's chief electoral officer, appointed Grenier to investigate the allegations into Option Canada in January 2006 after two authors uncovered documentation.

Normand Lester and Robin Philpot, who have sovereigntist sympathies, exposed the papers for their book Les Secrets d'Option Canada. The book alleged that Option Canada received $5.2 million from Heritage Canada to promote linguistic duality, but the money was used to pad the No committee finances instead.