Alberta's premier and finance minister both called for an apology Thursday from one of their harshest fiscal critics, after the public learned that MLA Derek Fildebrandt collected money by renting out his downtown Edmonton condo while claiming thousands of dollars in housing allowances.

For his part, Fildebrandt tried to dismiss the turmoil as a "smear" campaign and said in a statement he will remit the money to the province and continue to focus on more important issues.

"Rather than focusing on complaining about people trying to smear him, he should acknowledge that it was a mistake and he should apologize," Premier Rachel Notley said from Hardisty, Alta., where she attended a ceremony to mark the beginning of construction on the Line 3 pipeline project.

Fildebrandt, elected in 2015 as MLA for Strathmore-Brooks and finance critic for the now-defunct Wildrose party, rented out his Jasper Avenue apartment several times between January and March, while claiming $7,720 in taxpayer-funded accommodation allowance.

"I have a vehicle that sometimes is parked," Notley said. "It is not my intention to rent it out to Uber, nor is it my intention to pocket the money from that. I think that ultimately, going forward, Mr. Fildebrandt needs to think about the consistency between the positions he has taken in the past and his own behaviours. You can talk the talk but you need to walk the talk, and I don't think that he has been."

Finance Minister Joe Ceci also called on Fildebrandt, the former Alberta director of the Canadian Taxpayers Federation, to apologize.

"The public puts a lot of faith in their elected officials, and when people act like that I think they destroy that faith," Ceci said Thursday at a news conference to announce a draft agreement for a new city charter.

"I think it's clear that it's wrong, and I think he owes the people of Alberta an apology for his actions. It's incumbent upon all of us to act in the highest regard with regard to taxpayer funded monies, and to apologize when we do things that are wrong."

Fildebrandt should produce all records pertaining to his Edmonton apartment and be investigated for "double dipping," said Alberta Party Leader Greg Clark.

Clark said he has written to the Speaker asking for an audit of all MLA living expenses, and asking that rule-breakers be financially penalized.

"Albertans don't like hypocrisy," Clark said in an interview with CBC News.

"Derek Fildebrandt broke the rules. He's using taxpayer dollars to line his own pockets. There is no way he can get out of this."

In an emailed statement on Thursday, Fildebrandt confirmed he has been renting his subsidized Edmonton apartment through Airbnb when he isn't using it.

"I confirmed that letting out my Edmonton home while it is not being used is compliant with the rules," Fildebrandt said. "Letting out an unused residence is reasonable and a part of the modern sharing economy."

Alberta Party leader Greg Clark accuses United Conservative Party MLA Derek Fildebrandt of betraying public trust by subletting his apartment. 0:46

MLAs from ridings outside the Edmonton region are allotted a maximum housing budget of $23,160 each fiscal year to buy or lease a property in the city.

But government rules state that the allowance can be only be used to cover the actual costs incurred by members.

'The rules are clear'

Clark said Fildebrandt should be subject to a provincial investigation.

"The rules are clear," he said. "MLAs can only claim an allowance for accommodation reflecting their actual costs, but there are no penalties if the rules are broken.

"I believe very much that he has broken the rules. And more than just paying back the money he has gained from breaking the rules, there should also be a penalty.

$2,555 over 8 months letting out my Edmonton home while unused. I won't let smear distract from real issues & donate to the AB debt. <a href="https://twitter.com/hashtag/ableg?src=hash">#ableg</a> —@Dfildebrandt "Ethics is what you do when no one is looking."

Fildebrandt's Jasper Avenue unit appears to have been rented out several times between January and March, with eight guest reviews being posted for the apartment.

According to title searches, Fildebrandt does not own the apartment.

The MLA has said he's done nothing wrong and suggested it was completely reasonable to rent out his often-vacant apartment.

He has not responded to CBC News requests for comment but tweeted Thursday morning that he will "donate" $2,555 to help pay off Alberta's debt.

He described the controversy as a political "smear."

When asked to comment on the controversy, an official with the Speaker's office said a Member Services subcommittee is already reviewing MLA expense claims.

The revelations about the taxpayer funded apartment are especially damning given Fildebrandt's history as finance critic and taxpayer advocate, said Clark.

"His excuses ring hollow," Clark said. "Even if there is some loophole that allows him to do this, it's still wrong."

"I don't think most MLAs behave this way ... this erodes public confidence in the process."

United Conservative Party caucus deputy leader Mike Ellis told CBC News that Fildebrandt's expense claims are under review.

A spokesperson for Jason Kenney's leadership campaign said Fildebrandt has done "the right thing" by agreeing to pay taxpayers back the money he collected from the apartment.

Brian Jean has declined to comment on the controversy.