by John Kerin

Operation Sovereign Borders military chief Lieutenant General Angus Campbell will take over the job of Army Chief from May as part of a reshuffle of the armed forces leadership.

Prime Minister Tony Abbott also announced a new Chief of Air Force with  Air Vice Marshal Gavin Davies who gets a promotion to Air Marshal in taking over from Air Marshal Geoff Brown, from July 1.

Lieutenant General Campbell's promotion was one of the most widely anticipated of recent years after he took responsibility for the government's operation to stop asylum seeker boats and was viewed as a rising khaki star.

"General Campbell is familar to you as the head of Operation Sovereign Borders over the last couple of years," Mr Abbott said at a press conference in Canberra.

"He has done exceptional work in this very difficult job," Mr Abbott said.

From a peak of more than 3000 asylum seekers a week in July 2013, Campbell guided the government's on water operations to reduce boat arrivals to a trickle.

The result was largely attributed to the government's policy of turning back boats carrying desperate asylum seekers from Iran, Afghanistan and elsewhere back to Indonesia, despite Indonesia's displeasure.

General Campbell received plaudits for his oversight and the professionalism of Navy crews involved in the operation and he takes over at a time of high operational tempo with Australia deploying ground forces to support the fight against Islamic State/Daish in Iraq and Syria.

General Campbell replaces the high profile Army chief Lieutenant General David Morrison whose tenure was extended for an extra 12 months to complete a restructure of the Army and see a multibillion armoured vehicle project through its initial stages.

General Morrison crusaded to raise standards in the army, particularly to stamp out bullying, misconduct and discrimination which earned him international renown.

Mr Abbbott praised General Morrision as a "ground breaking, path finding Chief of Army".

Air Marshal Gavin Davies is a former F111 pilot and has been Deputy Chief of the Air Force for the past three years.

Davies comes to the top job with the Air Force involved in ISIS bombing and surveillance operations in Iraq and supporting allied attacks through the use of airborne early warning and control aircraft in Syria.

Australia has also deployed transport and refuelling aircraft to support allied operations.

Mr Abbott said Davies was taking over at a time when Australia had a "strong air component" in the Middle East.

"Air Vice Marshal Davies has been a pilot of distinction...he has had a series of senior commands including senior roles in our air operations in the Middle East," Mr Abbott said.