The Liberals are calling on the federal ethics commissioner to resume her investigation into what role 11 PMO staffers played in striking a deal with embattled Senator Mike Duffy to repay questionable expense claims.

The deal, cooked up in the Prime Minister's Office, led to bribery charges being laid against Duffy last week.

Mary Dawson began an investigation after it was revealed former PMO chief of staff Nigel Wright had provided Duffy with more than $90,000 to pay back illegitimate expense claims.

The rules governing her office forced Dawson to suspend her probe when the RCMP took up the case in order to not compromise the criminal investigation.

The RCMP announced last week that 31 criminal charges, including fraud, breach of trust and bribery, have been laid against the suspended senator.

The Liberals said Wednesday the way is now clear for the ethics commissioner to resume her work.

"I think Canadians don't want this to wait until Mr. Duffy has exhausted all of his legal avenues, that could take years," said Liberal MP Geoff Regan.

Although Duffy is charged with corruptly accepting money in his official capacity as a senator, Wright, who eventually lost his job in the PMO over the payment, has not been charged.

  • See the Liberals' letter to Mary Dawson below