The Northern Territory's Deputy Chief Minister, Robyn Lambley, has resigned from her position.

The Member for Araluen says the Country Liberals' parliamentary wing will meet on Wednesday to elect a new deputy leader.

"The Government has made a number of extremely tough but necessary decisions since taking office in August," she said in a statement.

"The Government has taken the first steps towards rolling back Labor's unsustainable debt and I understand these measures were unpopular with many Territorians."

A week ago, Chief Minister Terry Mills said Ms Lambley had his full support.

Her resignation is likely to trigger a cabinet re-shuffle, but she will retain her position as Treasurer.

It is also possible Mr Mills could again face a leadership challenge tomorrow after a botched attempt last month.