Aboriginal Affairs Minister John Duncan has resigned from cabinet, saying it was inappropriate for him to write to a tax court on behalf of a constituent more than two years ago.

In a statement released Friday afternoon, Duncan said he wrote a character reference letter on behalf of someone and sent it to a tax court judge in June 2011.

“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,” Duncan said. “I have therefore offered my resignation as Minister of Aboriginal Affairs and Northern Development to the Prime Minister, which he has accepted.

“I take full responsibility for my actions and the consequences they have brought.”

Heritage Minister James Moore will take over Duncan’s duties until a new aboriginal affairs minister is appointed.

Duncan will remain an MP for Vancouver Island North.

Cabinet members were asked to review their correspondence after The Canadian Press reported that Finance Minister Jim Flaherty urged the Canadian Radio-Television and Telecommunications Commission to grant a licence to a radio company in his Ontario riding.

Government rules prohibit ministers from influencing such tribunals.

The subsequent review by Duncan’s office led to the discovery of his character reference letter.

In a brief statement, Prime Minister Stephen Harper thanked Duncan for his “many contributions” and service to Canada.

But the minister was often criticized for his approach to the aboriginal affairs file. As the recent Idle No More movement intensified, Duncan was accused of poor leadership and failing to engage in meaningful discussions with First Nations leaders.

Pam Palmater, one of the leaders of the movement, told CTV News Channel Friday that Duncan was “the most inept” minister of aboriginal affairs in recent times.

“He didn’t take any action on some of the major files,” Palmater said, citing the housing and poverty crisis in northern Ontario’s Attawapiskat community and the headline-grabbing hunger protest by its chief, Theresa Spence.

“It’s just failure after failure after failure to communicate with First Nations and actually develop a relationship,” she said.

With files from The Canadian Press