Prime Minister Stephen Harper has filed a notice of libel against Liberal Leader Stéphane Dion and the Liberal Party of Canada over statements on the party's website regarding the Chuck Cadman affair.

In a March 3 letter sent to Dion, Deputy Leader Michael Ignatieff and Liberal House leader Ralph Goodale, lawyers for Harper describe two articles on the Liberal website as "devastatingly defamatory."

The articles relate to allegations that Conservative operatives offered Cadman, an Independent MP, a bribe of a million-dollar life insurance policy to vote against the Liberals in May 2005 and bring down the government. Cadman was battling cancer at the time, and died in July 2005.

"These malicious and reckless defamatory statements impugn the reputation of Prime Minister Stephen Harper," the letter states.

The libel notice cited a Feb. 29 article published on the Liberal Party's website entitled, "Harper knew of Conservative Bribery" and a Feb. 28 story that ran with the headline, "Harper must come clean about allegations of Conservative bribery, Liberals say."

While members of Parliament are protected from libel action for statements made inside the House of Commons, they can be sued for anything said outside.

"The defamatory statements are egregious. The articles in issue are not a fair and accurate report of proceedings in the House of Commons and are not privileged," according to the legal letter.

"Further, the statements complained of were made maliciously and with a reckless disregard for the truth, destroying any privilege that may have existed," it stated.

The allegations of a bribe, made by Cadman's widow Dona, are contained in a yet-to-be released book, Like A Rock: The Chuck Cadman Story, written by Vancouver journalist Tom Zytaruk. Last week, Cadman's daughter Jodi backed up her mother's story, saying her father discussed the alleged offer with her.

The letter demands the articles be removed from the website and that Dion read in English and French, "We apologize to the prime minister for the unfounded attacks made on his reputation."

The Liberals made no such apologies during question period on Monday afternoon. In fact, Dion told the House that it was going to take more than the threat of lawsuits to stop the Liberals from getting to the truth and demanded Harper immediately call the RCMP to investigate the allegations contained in the book.

Harper accused the Liberals of engaging in "more and more extreme allegations" and going to the point last week of publishing allegations of criminal misconduct on his part. 

"This will become the biggest error in judgment of his career," Harper said, adding the government doesn't direct the activities of police.

Earlier, the Liberal Party issued a release saying, "neither Mr. Dion nor any member of the Liberal Party will apologize." It described the measure taken by Harper as libel chill.

Cadman's vote was critical

The controversy dates to May 19, 2005, when the governing Liberals were facing a crucial vote on a budget amendment. The minority Liberals needed Cadman's vote to stay in power while the Conservatives, led by Harper, needed Cadman's support to force an election.

Cadman sided with the Liberals, ensuring Canadians would not have to head to the polls for a summer election.

In the book, Zytaruk writes that Chuck Cadman was visited by two Conservative party representatives in his office two days before the crucial vote and presented with a list of enticements to side with their party, including an offer of a million-dollar life insurance policy.

Harper has said there is "absolutely no truth" to the allegations and has pointed out that Cadman himself said in a national television interview that there had been no offer to win his support.

But Harper is quoted in the book saying that the offer to Cadman was "only to replace financial considerations he might lose due to an election." He adds that the offer was carried out by people who were "legitimately representing the party."

He also tells Zytaruk that he knew there was little chance Cadman would agree.

"They wanted to do it, but I told them they were wasting their time. I said Chuck had made up his mind," Harper says, whose comments were recorded on tape.

On Monday, Dona Cadman issued a news release saying she believed Harper when he told her that he didn't know about the offer. She added she wouldn't be running as a Conservative in her riding of North Surrey if she didn't believe him.

The CBC's Keith Boag said the Tories do not intend to issue a notice of libel to anyone else, suggesting that there are no plans to take legal action against the publisher of the book, Zytaruk or Dona Cadman.

Libel lawyer Peter Jacobsen said he didn't think Harper has a case against Dion, Ignatieff and Goodale unless he could prove that they were the individuals who published the comments on the Liberal Party website.