Liberal MP Ruby Dhalla resigned as the party's multiculturalism critic on Wednesday. (Jason Scott/Canadian Press)

A parliamentary committee of MPs said Thursday it will ask Ruby Dhalla to answer claims of nanny abuse, as the Liberals accused the Conservatives of a "lynch mob" mentality.

The move comes after Dhalla asked federal ethics commissioner Mary Dawson to review allegations of abusive and illegal behaviour involving two live-in caregivers hired to look after her mother.

"I have been saddened and troubled by the allegations made against my family and I this week," Dhalla, MP for the Ontario riding of Brampton–Springdale, said in a written statement.

"I take these allegations very seriously and believe a transparent, third-party evaluation of the facts is required."

Dhalla said she asked Dawson to review the allegations so that "this matter is resolved in a fair and objective manner."

She resigned as the Liberal party's multiculturalism critic on Wednesday after the allegations surfaced, prompting colleagues, including Michael Ignatieff, to distance themselves from the high-profile parliamentarian.

The affair erupted just as a parliamentary committee released a study report Wednesday that chronicles the ill treatment frequently afforded temporary foreign workers, including those in the federal Live-In Caregiver Program.

Conservative MP David Tilson, who chairs the Commons committee on citizenship and immigration, said committee members will look into the allegations.

"Two nannies… are saying that their rights have been violated," Tilson said. "That is the very topic we are looking at, the issue of whether migrant workers,... their rights, have been violated. Maybe they have; maybe they haven't. The committee's going to look at that."

Tilson said Dhalla is being invited to appear before the committee next week to respond to complaints about how her family treated domestic workers.

The two caregivers are also being asked to attend, he added.

Meanwhile, the Toronto Star reported Thursday that a third foreign worker has come forward to say she has been mistreated by the Dhalla family.

Dhalla, whom sources said is "devastated," has shown no intention of resigning her seat in the House of Commons.

After accepting her offer to quit her critic's role, Ignatieff put out a brief release stating that he looks "forward to a determination of the facts."

Sources said the caregiver allegations dominated Liberal conversations Wednesday. Dhalla was an ardent, early supporter of Ignatieff's leadership, but several MPs privately acknowledged he is purposely keeping his distance from what could become a political hot potato that damages the party among its core support base — women and immigrants.

Magdalene Gordo and Richelyn Tongson allege earned $250 a week working 12- to 16-hour days at the Dhalla family home in Mississauga, Ont., and that Dhalla seized their passports.

The women also allege they were illegally hired without the necessary approval under the federal Live-In Caregiver Program, and that other family members made them wash cars, shine shoes and clean chiropractic clinics owned by the Dhalla family.

The allegations fuelled Conservative attacks in both Ontario's provincial legislature and on Parliament Hill.

Tories at Queen's Park in Toronto and in the Commons demanded to know why the provincial labour minister hadn't responded to the allegations, made at a public forum two weeks ago.

Program is vulnerable to abuse: report

The new report from the citizenship and immigration committee appeared to suggest the government can and should do more.

The report said the Live-In Caregiver Program is vulnerable to abuse because it ties immigration applications to successful completion of a work period.

"Witnesses suggested the caregivers tolerate poor working conditions to meet the employment requirements," said the study.

The report made a series of recommendations calling for greater oversight and education of foreign workers.

The Conservatives on the panel, in a dissenting report, disagreed with 10 of the 36 recommendations, including one calling for a government response to all complaints.

"We oppose efforts to create an unnecessary advisory board, or to require the government to respond to the comments of every group or individual who chooses to express a view," said the Conservatives on the committee.

The report also said it takes too long to accredit workers under the caregiver program, and that workers who switch employers for any reason can be left in legal limbo.

Liberal MP Bob Rae, who appears to be the public spokesman on the matter, came to Dhalla's aid, saying that asking her to appear before the House committee is "a partisan tactic."

"It's a feeding frenzy and I think we should put it in perspective. We're deeply committed... to fairness and justice for caregivers. And if there's an investigation that's required, let it take place. But don't turn it into a political lynch mob."

With files from The Canadian Press