The book suggests the huge fee should be paid back to 14 countries, not including a figure for black Brits, and argued if the UK pays off reparations over 25 years with an interest rate of 2.5%, it would equate to around £740billion per year.
But over the years, Lenny has faced backlash over his own perceived "racism" - admitting to making racist jokes as a "survival technique".
He said on This Morning in 2024: "I started off as a 16-year-old copying people I'd seen on the television so I told racist jokes about myself and when I watch it now I go I wish I hadn't done that. But actually if wishes were horses, beggars would ride, so now you've got to learn from the mistakes you've made and move on into the future and try and get better role models."

In his 2019 autobiography Who Am I, Again?, he wrote: "If you were black and on TV in the 1970s, the jokes told tended to be against yourself rather than about any other subject.
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"Rule number one seemed to be: get all the dodgy racist jokes in before they did."
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He added to The Times: "People used to say Lenny was the only one who didn't need make-up. It was half funny once, but to hear that every day for five years was a bit of a p**ser."
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He received backlash from fans, with one writing: "Play this to anyone who considers Mr Henry a serious voice on racism."
Another added: "I cannot stand hypocrites. Henry is one of the biggest. Why he has a knighthood I'll never know."
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He said in 2022 that he regretted the character, telling GQ: "I probably wouldn't do that now. He'd have to be woke. You know, 'girl, I respect you'. You'd have to be like that.
"'I reserve the right to respect you and be a proto-feminist myself'. I think it would all have to change. And that's a good [thing]."
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He also offered to "strim her borders", "rummage around in her hedge" and "erect an unnecessary water fountain" to a shocked Mrs Johnson.
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