By David Ljunggren
OTTAWA (Reuters) - Canadian Aboriginal Affairs Minister John Duncan resigned unexpectedly on Friday after admitting he had inappropriately written a letter to a tax court on behalf of a constituent.
Duncan leaves a month after thousands of unhappy natives mounted protests across Canada about poor living conditions.
Duncan is the first minister to resign on a point of accountability since the Conservatives of Prime Minister Stephen Harper came to power in early 2006 vowing to clean up Ottawa.
Finance Minister Jim Flaherty was formally reprimanded last month for urging the telecommunications regulator to grant a radio license to a company in his Parliamentary constituency. He kept his job.
Duncan said he had sent a character reference letter to the court in June 2011 on behalf of a constituent who was dealing with the Canada Revenue Agency.
"While the letter was written with honorable intentions, I realize that it was not appropriate for me, as a Minister of the Crown, to write to the Tax Court. I have therefore offered my resignation," Duncan said in a statement.
Government ministers are not allowed to lobby regulators or other authorities in their capacity as cabinet members.
The official opposition New Democrats said the case showed the government had ethics problems and complained that it was inconsistent for Duncan to resign and Flaherty to stay in his job.
"It seems like they're increasingly out of touch with everyday people in terms of how you apply fair rules," senior legislator Paul Dewar told the Canadian Broadcasting Corp.
WRITING TO JUDGE "A DEFINITE NO-NO"
A government official said there was a big difference between writing to a regulator about a radio license and Duncan's lobbying of the federal Tax Court.
"Writing a letter to a judge ... is a definite no-no," the official told Reuters, referring to Duncan's case.
Parliament is not sitting next week so the opposition will not have a chance to raise Duncan's resignation quickly in elected House of Commons.
Although Harper is in no danger of losing power - the Conservatives have a majority of seats in the House of Commons and the next election is not until late 2015 - the resignation follows a series of setbacks.
Earlier this week, a Conservative member of the upper Senate chamber was suspended after being charged with sexual assault. Two other Conservative senators are being probed over whether they claimed excessive expenses.
Last March, the federal ethics commissioner ruled that Industry Minister Christian Paradis had violated ethics rules by telling bureaucrats to set up a meeting with a former Conservative legislator who wanted to do business with Ottawa.
After the same commissioner reprimanded Flaherty last month, he said he had meant to send the letter in his capacity as a legislator and not as a minister. He blamed staff for the error.
The government official told Reuters that after the Flaherty case, ministers had been told to review their correspondence. Duncan then discovered the tax letter and offered his resignation to Harper.
"Minister Duncan was very involved in his portfolio ... I don't think any prime minister is happy to lose a minister," the official said.
Aboriginal affairs is one of the trickier portfolios. Last month some native leaders said they were ready to damage the economy unless Ottawa addressed the poor living conditions and high jobless rates facing many of Canada's 1.2 million natives.
Heritage Minister James Moore will take over Duncan's duties until a new minister can be named. Duncan, who had heart valve replacement surgery in December 2010, will continue to serve as a legislator representing his constituency in British Columbia.
(Reporting by David Ljunggren; Editing by David Brunnstrom)