Liberal Leader Michael Ignatieff called gaffe-prone Conservative MP Helena Guergis a liar Wednesday, after she denied knowing that her staffers had written glowing letters about her to newspapers while posing as regular voters.

"If they have someone make up little letters, in my book that's lying," Ignatieff told reporters outside caucus. "And then pretending that you didn't really have anything to do with it, it was all the staff -- that's lying a second time."

"I don't think a person like that is worthy of the confidence of Canadians," Ignatieff went on. "I don't think that person is worthy of remaining in the cabinet of Canada."

Ignatieff's harsh words followed demands from his party that Guergis step down amid the controversy.

P.E.I. Liberal MP Wayne Easter said he cannot understand why Guergis, the minister responsible for the status of women, keeps her job.

"The prime minister's code of conduct states: ministers must act to ensure public trust and confidence, yet this minister continues to abuse the public trust without end," Easter said Wednesday during question period in the House of Commons. "How can the prime minister condone this kind of behaviour by this minister?"

Guergis herself declined to comment on the issue during question period. Transportation Minister John Baird noted Guergis had already addressed the controversy on Tuesday, and urged the House to get on with serving the interests of Canadians.

Guergis has been in the political crosshairs since February when she threw a tantrum at the airport in Charlottetown, and apologized for the "inappropriate" letter campaign Tuesday.

"We did discuss that it was inappropriate," Guergis told the House Tuesday of her conversation with one assistant, Jessica Craven.

"She apologized and assured me that it will not happen again."

But after she apologized for Craven writing to local newspapers in her Simcoe-Grey riding northwest of Toronto, it was revealed Tuesday night that her spokesperson, Valerie Knight, had sent a glowing letter to Maclean's magazine as well.

The Liberals also say several other people related to Guergis, including a former riding association president, wrote letters without disclosing their connections to the minister.

Guergis' employees did not reveal who they worked for in their letters. In the letters sent to the newspaper, Craven used her married name, Jessica Morgan, and not her professional name.

In both cases, the letter writers said their boss was unaware of their letters.

In a statement issued earlier Wednesday, Easter didn't buy that defence, saying all cabinet ministers have a media clipping service that notes all references in newspapers. He said it was "unfathomable" that Guergis or someone in her office did not know about the letters.

Chorus against Guergis gets louder

Easter is hardly the only one calling for Guergis to step down. Conservative commentator and former spokesperson for Prime Minister Stephen Harper, Kory Teneycke, wrote on his Twitter account that right the move for Guergis is to resign before her next gaffe.

CTV Ottawa Bureau Chief Robert Fife said that Guergis has lost support within the Conservative caucus and there are people in the Prime Minister's Office who would like to see her be forced to step down.

"But so far the prime minister is sticking with her through thick and thin," he told CTV News Channel Wednesday.

NDP political strategist Brad Levine called Guergis' missteps "an embarrassment to the Harper team," and predicted she would be moved out of cabinet during a shuffle, perhaps around Canada Day.

"I think what Mr. Harper is going to do is he will shuffle her out, but he won't do it right away," Levine told CTV's Power Play. "If he does then it's a victory for the opposition and I think he's smarter than that."

Liberal strategist Warren Kinsella said the incident should remind all MPs and their staff that such antics can easily be exposed in the Internet age.

"Political parties have been involved in sending letters to the editor since time immemorial," Kinsella told Power Play. "The difference is in the digital age you get caught. It's a dumb thing to do and it amazes me that people are still doing it."

Ironically, the situation rings similar to an incident involving Guergis' husband, former Conservative MP Rahim Jaffer.

Jaffer was forced to apologize after it was discovered an aide impersonated him in a radio interview.

The power couple has had their share of political problems in the last six weeks. Jaffer made headlines in March after charges of drunk driving and cocaine possession were dropped after he struck a plea bargain for a lesser charge.

The judge in the case told the former MP he should "recognize a break when you see one."