Speaker of the House Peter Milliken will not rule on whether Foreign Affairs Minister Peter MacKay referred to Liberal MP Belinda Stronach as a dog.

Because there is no official record of the alleged remark, Milliken said Monday, it's not up to the Speaker to "decide where the truth lies."

"I regret that the chair can offer no remedy to the House," Milliken said, adding the situation "does nothing to enhance the reputation of the House of Commons and its members."

Milliken referred to a 1991 ruling by Speaker John Fraser, who said that when the official record cannot back up an alleged comment, it's not the duty of the Speaker to resolve the issue.

MacKay has repeatedly denied making the remark, although eight Liberal MPs have sworn affidavits as to what they said they heard.

The alleged incident took place during parliamentary debate about the government's clean air plan.

One Liberal MP asked MacKay about the impact of pollution on humans and animals, adding: "What about your dog?"

MacKay allegedly motioned in response toward Stronach's vacant seat and replied: "You already have her."

Stronach, a former Tory leadership contender, had a high-profile breakup with MacKay when she crossed the floor to join the Liberals in May 2005.

The couple had been dating for months, and MacKay retreated to his father's farm in Lorne, N.S., giving several emotional interviews with a dog by his side and declaring his heart was "a little banged up."