John le Carré’s stinging disdain for British politicians is displayed in a caustic letter to an American friend, coming up for auction, which sees him pouring scorn on the Tories, the Liberal Democrats and Labour alike.

The handwritten letter to an obstetrician from Maine was written by the author in August 2010, after the Conservative party had failed to win a majority in the general election and had formed a coalition with the Liberal Democrats. Or as Le Carré astringently put it: “The Etonians have taken back the shop with the help of some B-list inexperienced liberals who will evaporate in their own hot air before long, leaving the shop to a ragbag of ivy league Tories, born again PR men, sexists, anti-Europeans, nostalgists and eco-ostriches.”

Due to be auctioned on Wednesday by Lion Heart Autographs, the letter to Willard J Morse does not spare the Labour party of the day, which is described by Le Carré as a “wastrel government that was for the people, by the people, except it was run by one bad Scottish piglet (Blair) and one unhappy Scottish hog (Brown), who emptied the piggy bank for the people while they were about it”.

Le Carré, who has since described himself as “more radical in old age than I’ve ever been”, has spoken in the past of how he was thrilled when Labour was elected in 1997, but was quickly disillusioned by Tony Blair’s party. “We don’t have a single member of the Blair administration lifting a public finger against the ecological ruin that George W is promising in the United States,” he said in an interview with David Hare in 2001, adding: “I thought Blair was lying when he denied he was a socialist. The worst thing I can say about him is that he was telling the truth.”

From cold war spy to angry old man: the politics of John le Carré Read more

He ends with a condemnation of the late writer Christopher Hitchens, whom Le Carré describes as a “truly odious little twerp”, or “what our teachers used to call LMF – low moral fibre, or shit”. Hitchens had been a vocal supporter of the Iraq war, which Le Carré opposed, taking part in anti-war marches and writing in 2003 that “America has entered one of its periods of historical madness, but this is the worst I can remember, worse than McCarthyism, worse than the Bay of Pigs and in the long term potentially more disastrous than the Vietnam war”. Hitchens died in 2011.

While his more recent thrillers have often touched on contemporary issues – his 2008 novel A Most Wanted Man was seen by critics to be a direct critique of US president George W Bush’s forced rendition policy, while his 2010 novel Our Kind of Traitor looked at the influence of Russian laundered money on British institutions – Le Carré has always steered clear of writing polemics, saying he recognises that his readers might stop seeking out his novels if he becomes too political. “Story and character must come first,” he told David Hare in 2010. “But I am now so angry that I have to exercise a good deal of restraint in order to produce a readable book.”