OTTAWA — Vancouver Island North MP John Duncan resigned as aboriginal affairs minister on Friday.

Duncan announced he was stepping down after improperly advocating to a tax court on behalf of a constituent.

Cabinet members were recently asked to review their correspondence following revelations that Finance Minister Jim Flaherty had improperly promoted a business in his riding in its licence application to the Canadian Radio-television and Telecommunications Commission.

The federal ethics commissioner reiterated that such interventions by public office holders are forbidden.

Duncan said in a statement that a subsequent search by his office turned up his own improper advocacy.

“In June of 2011, I wrote a character reference letter to the Tax Court of Canada on behalf of an individual to whom my constituency staff was providing case work assistance on a Canada Revenue Agency matter,” Duncan said in the statement.

“While the letter was written with honourable intentions, I realize that it was not appropriate for me, as a minister of the Crown, to write to the tax court.”

Genevieve Salvas, the acting executive legal counsel for the Tax Court of Canada, said her office was just learning of the matter and had no comment.

Duncan said he offered his resignation to Prime Minister Stephen Harper and it was accepted.

Duncan will continue to represent Vancouver Island North but his cabinet duties will be taken up temporarily by Heritage Minister James Moore.

Jean Crowder, the NDP critic for aboriginal affairs and MP for Nanaimo-Cowichan, said it was good to see Duncan take responsibility for his actions.

Her colleague Paul Dewar said Harper appears to be showing an ethical double standard between Duncan and Flaherty, who both caught in similar breaches of the conflict code.

The prime minister “felt [Duncan] was expendable, I guess,” Dewar told CBC.

Harper spokesman Andrew MacDougall said different circumstances explained the differing consequences.

“Minister Duncan wrote to a judge as minister, an act Mr. Duncan acknowledged was inappropriate,” MacDougall said in an email.

“Mr. Flaherty personally inserted the line specifying he was writing as the member of Parliament for Whitby-Oshawa. As was said at the time, the insertion of the signature block was an administrative error by staff.”

Duncan, 64, has suffered from poor health and was seen as one of the Conservative government’s less-accomplished advocates during the last several months of First Nations’ protests.

With the prime minister having publicly committed to a new round of negotiations over treaty issues and land-claims settlements, the leadership of the Department of Aboriginal Affairs and Northern Development is likely to take on a much higher profile in the Conservative government.

“At this crucial time in First Nation, Metis and Inuit relations, the prime minister must move quickly to replace Mr. Duncan with a full-time minister, not someone whose time is split between three ministries,” said Jean Crowder, NDP aboriginal affairs critic and Nanaimo-Cowichan MP.

— With files from Jennifer Ditchburn

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