Joe Hockey's centre-piece budget plan to hand cash back to small businesses could be so popular it causes its own drain on the budget as unexpected millions scramble to take full advantage of the two-year scheme.

The Fairfax-Ipsos poll released on Monday showed 81 per cent of voters applauded the initiative and a sizeable 22 per cent intend using the accelerated depreciation provision also known as instant asset write-off.

That's great news for the struggling Abbott government politically but not such great news for the deficit-riddled budget as the 22 per cent take-up represents as much as a 19-fold increase of the estimated usage number in the budget.

Bank of America Merrill Lynch's chief economist Saul Eslake said the poll findings suggested many voters may not understand the scheme and have assumed it to be both wider in its eligibility criteria and more generous, believing it would pay out on a dollar-for-dollar basis on new equipment purchases by small businesses.