The ad appeared to deflect attention from the Liberals' Tuesday launch of a website aimed at revamping the image of their, at times, bookish leader.

The Tory web page, which was active until Tuesday morning, featured an image of "Professor" Dion at a school blackboard, followed by puffin flying over his head and dropping excrement on Dion's shoulder.

The puffin was mentioned last year by deputy Liberal leader Michael Ignatieff as a potential mascot for the Liberal party because the "noble" birds "work like hell" and "hide their excrement."

When asked about the site, Harper said he had not seen the specific ad, but had been assured by his national campaign manager that it was promptly taken down.

"We have enough differences with the Liberals without getting into that kind of thing," Harper told reporters at a campaign event in Winnipeg. "So it has been removed, and my apologies for having it up." More...