Lukaszuk said he was in his Edmonton-Castle Downs constituency when he knocked on the door of a home that displayed signs supporting the opposition Wildrose party.
Lukaszuk said he never shies away from homes with competitors' signs, and he says they're usually happy to speak with him.
But Lukaszuk alleged that the man who opened the door immediately recognized him, swore, and ordered him off the property while punching him.
The resident of the home, however, insists he never punched Lukaszuk and only touched him when the candidate refused repeated requests to leave.
"He just stood there and started arguing and saying 'Why don't you like me?' and 'What have I ever done to you?'" Al Michalchuk says. "He just wouldn't leave."
Michalchuk said he eventually put his hand on Lukaszuk's shoulder and "nudged" him, still asking him to leave. He said he also put his hand between his shoulder blades, but he said he was never abusive.
"I'm 67 years old, I've got severe asthma, I'm in the final stages of liver failure. I don't know how much longer I've got to live. I couldn't punch my way out of a wet paper bag," he said.
Lukaszuk has represented the riding for the governing Progressive Conservatives since 2001.
He claimed that he left the home right away and wasn't hurt, although he says the punch he says he received did hurt.
He said he has complained to police, but there is no word yet on charges.
Premier Alison Redford issued a statement late Saturday afternoon saying she was "dismayed" to hear about the situation.
"I have great faith that everyone who enters public life, regardless of their political affiliation, is dedicated to making our community better," Redford said.
"As politicians we agree to disagree — that's what democracy is about — but we stand together against violence."
Michalchuk said it's not the first time he's argued with Lukaszuk. He said he asked Lukaszuk to leave his property when he visited his home during the last election campaign, and he said he also had to ask several times to get Lukaszuk to leave that time, too.
He said this time around when Lukaszuk finally left, he told a campaign worker, "See, that's the guy I told you about."
Lukaszuk, however, said nothing like what happened Saturday has ever happened on any of his campaigns and said it's important to speak to his competitor's supporters because he's still their representative in the legislature.
"They'll give you an idea what's wrong with your platform and why they're choosing the other platform which usually elicits a good discussion for a few minutes," Lukaszuk said.
"Or simply they'll say thank-you for stopping by anyhow."
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