David Cameron's resignation honours list reveals a "serious type of very British corruption", his former policy guru has said.
Steve Hilton said the ex-prime minister's recommendations are a symptom of a "corrupt and decaying democracy".
Mr Cameron's nominations, which include a long list of rewards for personal aides, political donors and senior figures on the losing Remain campaign in the European Union referendum, have sparked widespread accusations of cronyism.
Major Tory donor, Vitol oil boss Ian Taylor, who is said to have been nominated for a knighthood, asked for his name not to go forward and Labour's deputy leader, Tom Watson, called for the system to be boycotted.
Mr Hilton, who was Mr Cameron's director of strategy, said the row should be used to reform the "whole rotten system".
In an article for The Times, he wrote: "David Cameron's resignation honours list is a symptom of a wider problem: our corrupt and decaying democracy. So let's not just be outraged about it - let's use this moment to bring about radical reform of the whole rotten system."
He added: "The corruption comes when the honours system starts to clash with democratic principles. The most obvious way this happens is when people who are not elected make the laws which we live under.
"We've just fought and won a referendum campaign on the principle that unelected bureaucrats in the EU should not have the power to impose laws on us.
"I'm not clear why this principle applies to unelected foreigners but not to home-grown appointees. The decision to leave the EU was a victory for people power. But that's just the start; until we have a fully elected legislature, we cannot call ourselves a true democracy.
"The other, even more serious type of very British corruption revealed by the resignation honours list is the fact that these honours - and even places in our legislature - can be purchased with political donations."