House of Cards, Michael Dobbs, 978-1-4711-2852-3.
An unscrupulous 1980s Conservative chief whip plots and schemes within a re-elected but weakened government. This is not really great literature: most of the characters are stereotypes rather than in any way rounded portrayals, and the writing felt a little pedestrian. Nevertheless it was fun to read and I can see why it was adapted for television multiple times.
A Very British Coup, Chris Mullin, ISBN 978-1-84668-740-2.
A far-left Labour politician becomes Prime Minister, and the establishment and the Americans set out to undermine him. In some ways timely as Harry Perkins partially reflects Jeremy Corbyn: however, importantly, he is considerably smarter and has the backing of his parliamentary party (and, at least initially, the country). As above the writing is not of the most dazzling style, and the characters are if anything even more 2-dimensional, but also as above, it got the job done.
Also, really, a more serious political work, focusing not on the process of climbing the greasy pole (and stamping hard on those below) but instead on the structure of UK politics (at least as it stood at the time). Amusingly, the book mentions US interception activities in Europe, three decades before Snowden and half a decade before Campbell.