Labor will target wealthy families and claim a $2.2 billion, 10 year saving as it toughens up the eligibility for family tax benefit part A on Friday.

The decision to tighten the rules on FTB-A is one of a number of measures designed to improve the budget bottom line that are expected to be announce by the federal opposition.

Tony Abbott's staff considered involving Australian troops in the conflict between Ukraine and Kremlin-backed rebels during the MH17 crisis, potentially making them targets, a leading defence scholar says.

Former Australian Army officer James Brown, writing in the latest Quarterly Essay, described Mr Abbott's handling of defence as "the clearest case in recent times of a prime minister struggling to grasp the limits of Australian military power".

On the MH17 response, Mr Brown said Australia's military planners "worked up options" for Mr Abbott to send as much as a brigade – about 3000 soldiers – onto Russia's doorstep to help secure the crash site, though this would have included a contribution of Dutch forces.

Previously it has been reported Mr Abbott flagged sending up to 1000 Australian troops to provide protection. In the end, Australia quietly deployed about 200 special forces soldiers in a low-key role supporting police investigators.