OTTAWA — Gerard Kennedy is suing the National Post newspaper for suggesting he promised to weaken national security policy in exchange for support from Sikh and Muslim groups in last year's Liberal leadership contest.

Kennedy, the kingmaker who ensured Stephane Dion's leadership victory, is to launch the libel suit Thursday.

A written statement obtained Wednesday by The Canadian Press indicates Kennedy is seeking damages. Should he win the suit, he is promising to donate any award to charities "working to further understanding about diverse communities in Canada."

"I believe untrue and odious allegations such as these need to be firmly contested," Kennedy says in the statement.

"I believe very strongly in the freedom of the press. But that freedom only works well if it is not abused."

The lawsuit was sparked by a February article in the Post by columnist Jonathan Kay.

Kay noted that Toronto MPs Navdeep Bains and Omar Alghabra delivered several hundred Sikh and Muslim delegates to Kennedy and, via Kennedy, to Dion at the leadership convention. He then suggested that the price of the two MPs' support was a promise to end two controversial investigative measures in the Anti-Terrorism Act.

Two months following the convention, Dion instructed Liberals to vote against extension of the two measures.

At the time, Prime Minister Stephen Harper charged that Dion was soft on terrorism and alluded to another newspaper article as the reason. That article claimed that police wanted to use one of the controversial provisions to compel testimony in the Air India investigation from Bains' father-in-law, among other potential witnesses.

Although Dion, Bains and Alghabra have also been upset by such allegations, Kennedy says in the statement that he's in the best position to challenge the "unfounded and defamatory allegations" published in the Post article.

"Ultimately, my name was on the campaign that is being maligned and that affects all of the hundreds of good people who were involved in that effort."