Opposition MPs continued to grill the Tories over the Chuck Cadman affair on Tuesday, but unearthed no new details about what was or wasn't offered to the Independent MP for his vote in May 2005.

During question period, Liberal deputy leader Michael Ignatieff said there's no dispute that Harper's two top advisers, Tom Flanagan and Doug Finley, met with Cadman on May 19, 2005.

It was also the day of a confidence vote in the Commons, and the fate of Paul Martin's Liberal government depended on the vote of Cadman, a former Conservative who had become an Independent MP.

"But we also know, based on statements from the Cadman family, that two Conservative operatives approached Chuck Cadman on May 17 with a financial offer of some kind," Ignatieff said. "So will the prime minister tell us who these two other operatives were? What does he have to hide?"

Ignatieff, other MPs from the Liberal party and Bloc Québécois MPs continued the line of questioning throughout question period.

Tory MPs stated repeatedly that there was only one offer made to Cadman on May 19, 2005, and that Cadman himself said so during a 2005 television interview.

"We wanted Chuck Cadman to rejoin our party," Prime Minister Stephen Harper said. "The party was prepared to assist Chuck Cadman in securing his [Conservative] nomination and to ensure financially and otherwise that he was able to fight a successful election campaign."

The controversy erupted last week with the publication of comments made by Cadman's wife Dona in a yet-to-be-published book by Vancouver journalist Tom Zytaruk.

In Like a Rock: The Chuck Cadman Story, Dona Cadman alleged that the Conservatives offered her husband a million-dollar insurance policy if he voted to bring down the Liberal government in May 2005.

Cadman, a B.C. member of Parliament, who was sitting as an Independent at the time, was battling cancer and died of it a short time later.

His vote with the Liberals allowed the minority Liberals to survive the confidence vote.

In an unprecedented move Monday, Harper issued a notice of libel against Liberal Leader Stéphane Dion and the Liberal Party of Canada over statements on the party's website regarding the Cadman affair.

The Liberals described the measure taken by Harper as libel chill.