Australians mistakenly believe the Federal Government gives 13 per cent of the budget to overseas aid projects, about 14 times higher than the reality, according to the findings of a new poll.

The survey of more than 1,500 Australians was carried out for the Campaign for Australian Aid - a joint initiative of the Micah Challenge and Make Poverty History coalitions - ahead of the release of the Federal Budget tomorrow. The campaign is calling on the Federal Government to reverse scheduled $224 million in cuts to Australia's foreign aid budget.

Tony Milne, campaign director for the Campaign for Australian Aid, said most Australians don't realise the country provides less than one per cent of its annual budget to aid. "This is not surprising as governments and politicians have often failed to adequately promote the benefits of aid and building a fairer world."

Mr Milne said that if the scheduled cuts aren't reversed, "Australia will become the least generous we've ever been in terms of providing aid".

Last month, 12 prominent Christian leaders wrote an open letter to Federal Treasurer Scott Morrison, urging him not to go ahead with the planned cuts to the foreign aid budget which they said come on top of $11 billion in cuts in recent years.

Cuts to the foreign aid budget were announced in December, 2014, by the then-Abbott Government. If fully implemented, they will see foreign aid fall to 0.22 per cent of gross national income in 2017-18 - a record low for Australia.