OTTAWA -- Finance Minister Jim Flaherty urged the federal broadcast regulator to grant a radio licence to a company in his Ontario riding even though government rules on cabinet responsibility forbid ministers from influencing the decisions of administrative tribunals.

In his letter to the Canadian Radio-Television and Telecommunications Commission, Flaherty praised Durham Radio Inc.'s ultimately unsuccessful bid to obtain a licence to operate a new FM station for the Toronto area.

The broadcaster, based in Flaherty's Whitby-Oshawa riding, was one of several applicants last year for the hotly contested spot on the FM dial. The company -- which already has country and rock radio stations in Oshawa and Hamilton -- was proposing an easy-listening outlet.

"Durham Radio has a strong track record for providing excellent service for their listeners and this puts them in a solid position to offer this new service," Flaherty wrote in the letter, dated March 30, 2012.

"As the MP for Whitby-Oshawa, I support their proposal and their application."

In a statement to The Canadian Press, Flaherty said he would "continue to be a strong advocate for the people and community I represent. It is my job."

The Prime Minister's Office also jumped to the veteran cabinet member's defence Thursday, saying he was merely performing the role of an MP.

However, Flaherty's signature on the letter notes that he is not just an MP but also finance minister and minister for the Greater Toronto Area.

The CRTC, which administers broadcasting and telecommunications, is among the federal agencies known as quasi-judicial tribunals -- court-like bodies that make decisions at arm's length from the government.

Federal rules on ministerial responsibility, including interaction with such administrative bodies, are set out in Accountable Government: A Guide for Ministers and Ministers of State. The document, last updated by Stephen Harper's government in December 2010, is posted on the prime minister's website.

The rules say decisions made by administrative tribunals often concern individual rights or interests, are technical in nature or are "considered sensitive and vulnerable to political interference (such as broadcasting)."

"Ministers must not intervene, or appear to intervene, with tribunals on any matter requiring a decision in their quasi-judicial capacity, except as permitted by statute."

The guide adds that although the minister or cabinet may have the authority to send back or overturn decisions once made, as is the case with the CRTC, "it is inappropriate to attempt to influence the outcome of a specific decision of a quasi-judicial nature."

The ministerial responsibility rules complement the Conflict of Interest Act, the federal law that governs the ethical conduct of cabinet members.

In his statement, Flaherty said that as an MP "my primary duty is to serve my constituents and represent the needs of my community which I do on a daily basis on a variety of different issues."

"As highlighted in the letter to the CRTC, I was offering support to a local radio station from my riding as the member of Parliament."

Liberal MP Scott Andrews, the party's ethics critic, accused the Conservatives of hypocrisy.

"They make rules and then they break rules and say they don't apply to them, and think they've done absolutely nothing wrong," he said Thursday.

"They've put a lot of words on paper but they've never lived up to them."

In a statement, the NDP said Flaherty showed a "lack of understanding of federal conflict-of-interest laws and guidelines."

Asked whether it stands by the guide for ministers, the Prime Minister's Office had no immediate response.

In an email, PMO spokesman Carl Vallee defended Flaherty, saying he "wrote a letter on behalf of his constituents, as members of Parliament often do."

Durham Radio president Doug Kirk said in an interview that he asked Flaherty -- as his local MP -- to provide the letter of support.

"I approached Jim through his office," Kirk said. The two have met a number of times, he added. "I know him reasonably well. He's a very busy guy, obviously."

Kirk also secured letters of support from two other Toronto-area MPs.

At a CRTC hearing in Toronto last May on Durham Radio's licence application, Kirk thanked Flaherty for "heartily" backing the bid, referring to him as "the honourable Jim Flaherty, MP for Whitby-Oshawa, minister of Finance for Canada and the minister responsible for the GTA."

In September, the broadcast regulator awarded the FM licence to an indie rock music station.

Flaherty's intervention in Durham Radio's application has gone unnoticed by the public until now.

Duff Conacher, a board member of watchdog group Democracy Watch, said Flaherty's letter violates not only the accountability rules for ministers but also the Conflict of Interest Act.

The conflict law says no minister shall use his or her position to try to influence a decision in order to "improperly further another person's private interests."

Conacher rejects the argument that a minister can claim to be acting solely as an MP when intervening with bodies such as the CRTC, "because you can't take off your minister's hat."

"It is improper to go this far," Conacher said.

It is acceptable to provide information to a constituent about applying to the CRTC, or to explain procedures to them, he said.

"But you don't help them win. You don't become their lobbyist."

Possible violations of the Conflict of Interest Act are investigated by federal ethics commissioner Mary Dawson.

Due to confidentiality requirements, the commissioner's office "cannot comment on the specifics of individual cases," spokeswoman Jocelyne Brisebois said after The Canadian Press requested comment on Flaherty's letter.

"Unfortunately, there is really nothing I can tell you at this point," Brisebois said. "Our office will, however, follow up with Mr. Flaherty's office in order to ensure we have a complete understanding of the circumstances involved."

Vallee said the finance minister plays no role concerning, and has no input into, the deliberations or decisions of the CRTC. "I would also point out that Durham Radio Inc.'s application was unsuccessful."

David Collenette resigned as defence minister in 1996 after it emerged that he wrote the federal immigration board seeking a review of a constituent's request for a speedy appeal hearing. The constituent was challenging the board's decision to reject an application for permanent Canadian residency for her husband.

Michel Dupuy faced calls for his resignation from the heritage minister's post in 1994 after writing a letter to the CRTC asking that a constituent's broadcasting application receive "due consideration."

In his letter to the broadcast regulator, which was copied to Kirk, Flaherty noted the Toronto area enjoyed a rich culture and that there was "a need to broaden the radio market to include a distinct, adult-oriented radio station that plays music that other stations do not."

"Durham Radio continues to promote Canadian music and artists not supported by any other media outlets. This application provides major initiatives to support and promote Canadian musicians."