Beleaguered Northern Territory Chief Minister, Terry Mills, has announced he has stepped down from the job after Local Government Minister Adam Giles successfully orchestrated the coup following a chaotic week in the Territory.

The 40-year old Mr Giles will become the first Indigenous head of state in Australia's history.

The announcement follows a frenetic week in Territory politics, where Dave Tollner was sacked from cabinet, Mr Giles was barred from challenging for thetop job and Westra Van Holthe was named Deputy Chief Minister.

It is expected that Mr Tollner will be reinstated to cabinet and take the position of Deputy Chief Minister from Mr Van Holthe.

Mr Mills, who issued a brief statement before embarking on his trade mission to Japan, was in Yokohoma when he was alerted to the fact that he no longer had the numbers to keep a hold on leadership.

The latest round of political blood-letting follows the standing down of Victorian Premier, Ted Baillieu, late last week.