On being re-elected to her Birmingham Yardley seat in July to a cacophony of boos, Jess Phillips declared that it had been “the worst election I have ever stood in”. Quite a statement from a woman who, in her nine years as a Labour MP, has already endured countless threats to her personal safety, leading to the installation of a safe room in her constituency office.

So why does she keep going? The answer is that she “fucking love[s] politics” and she has “not one jot of time for people who lazily think that politics is all pointless or that it is only being done by the same boring bureaucrats who are so far away from the people who vote for them that it will never serve anyone but those who play the game … What a gift that we so lazily dismiss as something that isn’t about us. What a thing to live in a country where, if you don’t like something, you can freely set about shifting it.”

That Phillips’s book arrives weeks after a landslide Labour victory is a shame. Her treatise on why democracy matters and how political apathy is for losers would have been more pertinent when an election was looming and the country still in the throes of Tory misrule; such is the way of publishing and its immovable deadlines. Still, it’s not as if Phillips is a new literary voice: 2017’s Everywoman, 2019’s Truth to Power and 2021’s The Life of an MP: Everything You Really Need to Know About Politics have all been smart showcases for her distinctive blend of enthusiasm and exasperation. Most MPs wait until retirement to start recording their life and times, but Phillips is not most MPs. She is funny, she swears like a sailor and has long made it her mission to demystify the workings of politics and the hallowed institutions in which it operates.

A mixture of memoir and polemic, Let’s Be Honest tackles the culture wars, specifically the confected outrage that erupts on social media and is then co-opted by politicians either to distract from their party’s failings or simply as a headline-grabbing exercise. “The internet has well and truly leaked all over politics. Westminster fucking reeks of the shit,” Phillips notes, advising us to “stop falling for the lie that these hot-button issues have any relevance in our actual lives”.

In a chapter called Smoke and Mirrors, she describes, with visceral horror, the experience of attending A&E last Christmas with a severe cough that was making it hard to breathe. Having been shunted from one waiting area to another, she ended up hooked up to a nebuliser and crammed with six other patients into a cubicle designed for one. Her point isn’t simply the egregious “failure of governance, planning and resource” by the Tory government that has led the NHS being on its knees, but the decision by the Conservatives during the spring budget to ignore the buckling health system in favour of announcing cuts to inheritance tax. This wasn’t for the benefit of the British people, the vast majority of whom will remain under the threshold at which the tax is paid. It was, she observes, “an act of division”, a policy created to bait the Labour party into denouncing it so that the Tories could then tell voters that Labour was planning to “steal your children’s birthright”.

Elsewhere, she looks back with a combination of mirth and derision at the fleeting premiership of “dangerous lunatic” Liz Truss who “increased my mortgage payments by £700 a month – a fact I like to remind her of with an accumulating total each time I see her walking as if butter wouldn’t melt through the vaulted halls of Westminster”. There is also a chapter on the infuriating nature of soundbite politics and on the ruinously expensive Rwanda deportation scheme, since binned by Labour, which “was born entirely out of the Tory government’s desire to have a row rather than an outcome”.

There is, inevitably, some overlap with her previous books as she seeks to convince us that politics really can effect change and that not all politicians are morally bankrupt. But there’s a reason why Phillips’s books end up on bestseller lists, and that is her lack of stuffiness, her sharp wit and don’t-fuck-with-me attitude. The writing here is conversational, irreverent and deceptively clever; it’s as if she and her reader are sharing a bottle of wine on a Friday night, leading to a level of candour that a more cautious politician might view as reckless but is very much Phillips’s USP.

Let’s Be Honest may feel a little dated on arrival but it is still fun to spend time in the company of its author and to share in her fury at the absolute state of things. Yet, while it’s good to rant, the most rousing moments come in Phillips’s defence of her career and the ways politics has changed her life. “Good politics literally gave me freedom as a woman to dare not just to vote, but to be voted for,” she writes. Now, for her, the real work begins.

• 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.