Ontario Liberal candidate Steve Del Duca has issued an apology for a campaign flyer that features an image of PC Leader Tim Hudak laughing maniacally as he walks away from an exploding hospital.

The flyer was distributed in the riding of Vaughan — located north of Toronto — where Del Duca is running for re-election. Similar images appeared in Liberal campaign ads published in the local newspaper.

The image appears to be inspired by the movie The Dark Knight with Hudak cast in the role of the Joker. The Liberals have attacked the PCs plan to cut 100,000 civil service jobs, which they say will result in reductions to health care and education.

A letter from Hudak's campaign manager called the image a "piece of terrorist literature." PC deputy leader Christine Elliott called the flyer "sickening."

Del Duca issued an apology on Twitter, saying "The flyer was a mistake for which I am sorry."

The image used in the flyer is the Photoshop work of Ishmael N. Daro, an editor with Postmedia, who distributed the image via Twitter in May. In an online post, Daro says he often creates Photoshop images of politicians as "a fun way to waste a few minutes before getting back to work."