Federal budgets have become "balance sheets of power", where special interests struggle for domination, World Vision boss Tim Costello says.
Mr Costello, whose brother Peter was treasurer in the Howard government, makes the comments in his latest book, Hope.
In the book, the Baptist minister and Order of Australia recipient reflects on his decades of work in poverty and emergency relief, and the Christian motivation behind it, as well as examines Australian and global politics.
Deeply personal and simply written, it is part-memoir and part-manifesto.
Mr Costello writes that politics had become a matter of "power and who gets what they want and who misses out".
"In Australia, a budget is simply the balance sheet of power and which special interest lobbyist won and who missed out," he writes.
Cutting back on development aid needs to be challenged, he says, because while charity is vital it becomes like "pouring water into a bucket with a hole in it".
Reflecting on his brother's political career, he writes: "Each person is entitled to make their own judgments on all things in life, be it politics, religion or their value system."
"My brother is a committed Liberal, a strong voice for conservative values - and in this, he is very akin to my parents' political persuasions.
"I became increasingly aligned with those looking for community answers, rather than always putting the emphasis on the rights, privileges and freedoms of the individual.
"But, saying that, I am not a political-party man. Too much of the maverick I think. Fortunately the world is big enough for all types."
Mr Costello says that while Peter had "lived out the family script", he had "confused" his parents.
"I know at times when the media has chosen to blow up the differences between us as brothers, it has caused them anxiety and concern. It is the price of public life and a price they had had to adjust to."