To paraphrase Rishi Sunak at the dispatch box the other week, politics comes at you pretty fast. Doubtless Jess Phillips expected and very much hoped her new book would be published before a general election was called. As she corrected her proofs, she cannot have known that by the time it squeezed its way into the nation’s bookshops, the election campaign would be long over, and she would find herself the new parliamentary under-secretary of state at the Home Office. All the people (I mean Tories) she complains about in its pages! Metaphorically speaking, they’ve evaporated into thin air. Though she somehow clung on to her seat, Esther McVey, previously so-called minister for common sense, is really only good for the GB News studio now, which means Phillips’s civil servants are henceforth free to wear their rainbow lanyards with alacrity, should that be their thing (McVey wanted to ban them).

Government is incredibly challenging, and one day in the future Phillips, the member for Birmingham Yardley since 2015, will surely want to reframe Let’s Be Honest, a text whose essential message may be summed up as: “Politics is a very fine thing except when it’s done by anyone other than me and my party.” Almost without exception, the only truly good books about life at Westminster are the work of ex-practitioners, their disillusionment rising from each page like steam from a giant cow pat (Rory Stewart’s Politics on the Edge is fascinating – and some of his descriptions of former colleagues certainly had me reaching for a clothes peg). But for now, we have only the volume that’s in front of us – and alas, its title is a bit of a hostage to fortune. Dishonesty takes many forms, and here it comes in the guise of the sin of omission; in the end, it’s hard to disagree with Phillips’s own analysis, which is that tribal politics is a sickness from which she suffers just as much as the next MP.

Phillips doesn’t like it when people moan that politicians are all the same. She isn’t, for one! But on the other hand, she knows what they mean. Large sections of her book, with its subtitle “Truth, Lies and Politics”, are devoted to criticising David Cameron, Boris Johnson and Liz Truss – though she also goes for fruit that is not so much low-hanging as soggy windfall, there simply to be scooped up. A Conservative MP called Nick Fletcher (“a political non-entity”) gets a good blast of her invective for doing “naff all” about young men and violence even as he complains that male role models such as the Doctor in Doctor Who and the Ghostbusters are being played by women (again, the good news is that Fletcher lost his seat at the election: his “meh-ness” will trouble her no more). I suppose it’s vaguely revealing to read that ahead of a visit by Cameron, a youth project on which she was working before she became an MP was given “thousands of pounds” of funding for a graffiti installation, to make him look edgy – though most of us long ago grasped he wanted briefly to be down with the kids. But generally, she’s telling us what we already know in buckets. Theresa May was paralysed by Brexit! Truss’s financial mayhem sent her mortgage repayments shooting up! And then there’s the writing. (Where was her editor?) Johnson, she says, is “shy and withering”, which makes you pause, the two things seemingly in contradiction. So you read on. Apparently, he has always looked “terrified” whenever she has met him in person… Ah, so she doesn’t mean withering but wimpy, maybe, or perhaps something else beginning with “w”?

Like many voters, I like Phillips, and admire her to a degree (never more so than on election night, as she struggled to speak above those who were trying to shout her down). I understand that she’s frantically busy: the groaning constituency workload, the long days in London far from her family. But why bother to write a book if you don’t have the time to do it properly? If you’re going to rely on quoting your husband, your brother and, sometimes, Wikipedia? If your best way of adding emphasis to your argument is to deploy again and again the word “fucking” (as in “fucking angry”)? It’s great that she believes in herself (this is her fourth book). But there is a lot of stuff here she should really leave to other people to write (“I don’t want to blow my own trumpet but there is literally no one elected in the UK and much of the world who would be better suited for this job than me”).

The best chapter is about violence against women, and what can be done to change it, an example she chooses as a means of illustrating what politics might be capable of were it to set its mind to a straight and committed course (and also because of her own undoubted expertise in this area). We need proper data, she says, which is interesting; we need funding, she says, which is less so. She’s right to emphasise that Labour must tell the truth on this subject: it will struggle to end this epidemic, even if targets are set. There is no quick fix. But she avoids some of her party’s recent issues when it comes to gender, the Equality Act and single sex spaces – failures of articulation that have left many women wondering if they trust Labour. If she’s perfectly right to say that the Tories have been dogged by more extreme wings of their party (for instance, the European Research Group), they’re hardly the only ones. Jeremy Corbyn does not appear in her book. Kate Osborne, the Labour MP for Jarrow and Gateshead East, has made nearly as many stupid and unacceptable pronouncements in my eyes as Miriam Cates, the former Conservative MP for Penistone and Stocksbridge (Cates is another of Phillips’s bugbears).

So, yes, let’s be honest. But let us not be selective. If Phillips’s book is a blueprint for the kind of politics she wants to see in the future, the plain speaking must apply to all; failure, if and when it comes, cannot be ducked, whoever is responsible. Anything else will only stoke the very disaffection and alienation she says she longs to dispel.

• Let’s Be Honest: Truth, Lies and Politics by Jess Phillips is published by Gallery (£20). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply