OTTAWA - The Liberals are asking the federal ethics commissioner to look into a big mortgage given to embattled Tory cabinet minister Helena Guergis.

They want to know if Guergis got preferential treatment to finance an expensive new home.

Liberal MP Marlene Jennings wrote to commissioner Mary Dawson on Tuesday, asking her to look into reports that Guergis was given a mortgage for the full $880,000 cost of the Ottawa home.

Jennings says reports suggest a Bank of Nova Scotia branch in Edmonton granted the mortgage without requiring a down payment.

She notes that the conflict of interest code for MPs stipulates that no MP or family member shall accept -- directly or indirectly -- any gift or benefit that might be perceived as an attempt to influence the MP.

Guergis, the minister of state for the status of women, came under opposition fire in February for throwing a tantrum at Charlottetown airport.

And last week, she faced further calls for her resignation after it was revealed that several current and former staffers had written letters to newspapers praising the minister -- without identifying their links to her.

Guergis's husband, former Edmonton Tory MP Rahim Jaffer, has helped keep the spotlight on the minister. He was fined last month for careless driving after charges of cocaine possession and impaired driving were dropped.