03/20/2013 04:54 EDT | Updated 05/20/2013 05:12 EDT

Stephen Harper, Bob Rae Debate Who's Uglier Over Penashue Scandal (VIDEO)

OTTAWA - Things got ugly in the House of Commons — literally.

With opposition accusations flying over the resignation last week of Labrador MP Peter Penashue, Prime Minister Stephen Harper again heaped praise on his former intergovernmental affairs minister.

Harper told the Commons he expected the Conservatives would run a clean campaign in a byelection in which Penashue has pledged to run.

But he also suggested the Liberals were already running a "negative, ugly campaign" against Penashue.

That prompted an exchange with interim Liberal Leader Bob Rae, with the Commons speaker forced to break up the verbal melee.

Rae told the House the Conservatives had only to look in the mirror if they wanted to see ugly.

Penashue resigned his cabinet post and his seat in the Commons last week after Elections Canada found his election campaign had accepted 28 different ineligible donations.

He has since pledged to run in a byelection, and is being supported by the prime minister, even though Elections Canada is continuing to investigate.

The opposition parties have accused Harper of acting immorally by allowing Penashue to run in a byelection after being caught "buying" his last election.

Penashue is a former Innu leader who defeated a Liberal incumbent by just 79 votes in the 2011 election.

The prime minister has said Penashue has accomplished much for his constituents, and should be allowed to face voters based on his track record.

Also on HuffPost