Liberal plans will create a deficit "to the tune of at least $12 billion," Conservative Leader Stephen Harper said Saturday.

Harper didn't explain where the number came from, but Liberal Leader Stéphane Dion has rejected the charge before.

"A Liberal government will never put Canada into deficit. Period," Dion has said on the party website.

Harper addressed Conservative supporters in Ajax, Ont., listing the government's accomplishments and warning that the opposition parties would put the economy at risk.

With the credit crunch affecting the United States, Canada needs stable leadership "to get through this troubled world economy."

Harper also talked Saturday about other federal spending — such as funding for transportation projects — in the Ajax area, which is east of Toronto.