The party says in a news release that Jason Soklofske, who is the NDP candidate for Medicine Hat, has been charged with simple assault following the incident.
The release says the altercation was with another individual on Saturday, but doesn't give details.
Cheryl Oates, a campaign spokeswoman for the NDP, wouldn't elaborate on the incident.
The release says the NDP has accepted Soklofske's decision to withdraw.
It says the party will announce a new candidate for Medicine Hat in the coming days.Alberta NDP Leader Rachel Notley says that she did not ask Soklofske to resign, but insists he quit on his own accord.
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