Australia's surging economy is being driven by a growing number of people raiding their savings, fuelling concerns that households already saddled with record levels of debt are over-extending themselves.

Treasurer Josh Frydenberg's first set of national accounts have delivered the Coalition the strongest set of numbers since the end of the mining boom, registering a bumper 3.4 per cent result and setting Scott Morrison up for an election fight based on his economic credentials.

But Wednesday's strong headline figure - which puts Australia ahead of the largest seven economies in the world - masks underlying concerns, including the reliance on high immigration numbers to drive employment growth and the fall in the household savings ratio to its lowest level in six years.

Treasurer Josh Frydenberg Credit:AAP

Treasury sources confirmed the falling household savings ratio was being watched closely, amid fears consumers could pocket their wallets when savings dry up and interest rates inevitably rise from their current historic low of 1.5 per cent.