Helena Guergis in the House of Commons in March. (Adrian Wyld/Canadian Press)

Federal Ethics Commissioner Mary Dawson says she "cannot pursue" an NDP request to examine the conduct of former cabinet minister Helena Guergis under the Conflict of Interest Act.

New Democrat MP Libby Davies sent a formal request to Dawson on Friday, asking her to look into whether a letter Guergis sent to a municipality in her riding, promoting a company her husband had ties to, contravened the law.

Davies made the complaint a week after the prime minister said he had referred allegations against Guergis to the RCMP and the ethics commissioner.

While Guergis was forced to resign as minister of state for the status of women and to leave the Conservative caucus, the ethics commissioner said she did not have enough information to investigate the matter raised by Davies.

Dawson said in her response to Davies that "you have not provided any information indicating Ms. Guergis was acting in her capacity as a minister of state."

The Conflict of Interest Act applies to cabinet ministers. Guergis sent the letter in question on her MP letterhead.

In an interview with the CBC, Davies said she is concerned about Dawson's interpretation of the legislation.

'A narrow interpretation'

"We're just going to review what she said to us in her letter and give a further response to her, but I am concerned that it seems like a narrow interpretation."

Davies said the NDP will make that argument to the ethics commissioner.

Davies was heartened that Dawson said she is looking into whether Guergis violated the Conflict of Interest Code for members of Parliament. The code applies to all MPs, not just cabinet ministers.

Guergis has 30 days to respond to that inquiry.

Meanwhile, her husband, former MP Rahim Jaffer, was set to testify Wednesday before the parliamentary government operations committee. NDP MP Pat Martin was unable Monday to reverse a motion calling on Jaffer to answer questions about the Green Infrastructure Fund. Martin said he was concerned that this testimony could interfere with a potential RCMP investigation.