What does Kevin Federline's upcoming book say about Britney Spears?

The ex-husband of Britney Spears makes a number of allegations against her - and she has accused him of attacking her.

Watch LiveBritish Broadcasting CorporationHomeNewsSportBusinessInnovationCultureArtsTravelEarthAudioVideoLiveDocumentariesHomeNewsIsrael-Gaza WarWar in UkraineUS & CanadaUKUK PoliticsEnglandN. IrelandN. Ireland PoliticsScotlandScotland PoliticsWalesWales PoliticsAfricaAsiaChinaIndiaAustraliaEuropeLatin AmericaMiddle EastIn PicturesBBC InDepthBBC VerifySportBusinessExecutive LoungeTechnology of BusinessFuture of BusinessInnovationTechnologyScience & HealthArtificial IntelligenceAI v the MindCultureFilm & TVMusicArt & DesignStyleBooksEntertainment NewsArtsArts in MotionTravelDestinationsAfricaAntarcticaAsiaAustralia and PacificCaribbean & BermudaCentral AmericaEuropeMiddle EastNorth AmericaSouth AmericaWorld’s TableCulture & ExperiencesAdventuresThe SpeciaListTo the Ends of The Earth EarthNatural WondersWeather & ScienceClimate SolutionsSustainable BusinessGreen LivingAudioPodcast CategoriesRadioAudio FAQsVideoBBC MaestroLiveLive NewsLive SportDocumentariesHomeNewsSportBusinessInnovationCultureArtsTravelEarthAudioVideoLiveDocumentariesWeatherNewslettersWatch LiveKevin Federline has held off writing about Britney Spears. Until now2 days agoShareSaveAna Faguy, James FitzGerald and Nardine SaadShareSaveGetty ImagesThe pair's divorce was finalised in 2007The ex-husband of pop star Britney Spears gives new details on the pair's tense relationship in his new memoir You Thought You Knew.

Kevin Federline, her one-time backing dancer, presents a picture of Spears's allegedly erratic behaviour as a wife and mother, and says he continues to have concerns for her wellbeing.

Spears has spoken out against the book, which will be published on Tuesday, and accuses Federline of trying to profit from his association with her.

Federline makes a number of allegations against Spears, in the memoir shared with the BBC ahead of the book's release by publisher Listenin.

He accuses Spears of unhealthy behaviour as a mother, including drinking when she was pregnant and taking cocaine while her two sons were still breastfeeding. Spears has previously denied having substance abuse issues.