I generally like Harris's work - his Cicero trilogy is excellent - but this is a bit of a potboiler. It reads like it's been bashed out in a couple of weeks.
It's about a prime minister having an 'affair' with a younger woman. But there's no actual sex involved. He should have written about Marguerite Steinheil and Felix Faure and his death by blow job. She went on to be acquitted of the death of her husband and died in Hove - now, there's a life worth writing about