Damian McBride denies memoir was about making money
2 October 2013 Last updated at 16:52 BST
In his book, Power Trip, Damian McBride revealed that while working as Gordon Brown's special adviser he regularly used smears and leaks in attempt discredit the former prime minister's rivals.
Mr McBride said he was being loyal to Mr Brown and insists the then chancellor of the exchequer was unaware of his actions.
When asked by HARDtalk's Stephen Sackur about whether he had written the book for financial reasons, Mr McBride said had "low expectations" about whether it would generate any money, adding that from the outset he wanted to donate the royalties to charity.
You can watch the full interview on BBC World News on Wednesday 2 October at 20:30 GMT and on the BBC News Channel at 00:30 on Thursday 3 October.