The 1960 obscenity trial that lead to the acquittal of Penguin Books for publishing DH Lawrence’s novel Lady Chatterley’s Lover is a seminal case in British literary and social history.

The verdict was an important victory for freedom of expression, and saw publishing in Britain become considerably more liberal.

It is credited as being a crucial step in liberalising the country’s cultural landscape, encouraging frank public discussion of sexual behaviour that meant sex was no longer a taboo in art and entertainment. It also shifted views on major human rights issues including the legalisation of homosexuality and abortion, the abolition of the death penalty and divorce reform.

The trial highlighted the gap between modern society and an out-of-touch establishment, demonstrated most tellingly in the opening remarks to the jury of the prosecutor, Mervyn Griffith-Jones: “Is it a book that you would even wish your wife or your servants to read?”

Now, almost 60 years later, the trial remains the landmark case in British obscenity law, and its wider cultural and historic significance was demonstrated earlier this year. An annotated copy of the book used by the trial judge, Sir Laurence Byrne, was sold at auction to an overseas bidder for £56,250, but the then arts minister, Michael Ellis, placed a temporary bar preventing its export.

English Pen, the charity and writers’ association that promotes freedom of expression and literature across frontiers, launched a crowdfunding campaign to keep the book in the country.

Philippe Sands QC, the writer, human rights barrister and president of English Pen, says that Lawrence is “unique in the annals of English literary history” and that the book “was at the heart of the struggle for freedom of expression” in the courts and beyond. Calling for support to keep the book in the UK, he says it is “a symbol of the continuing struggle to protect the rights of writers and readers at home and abroad”.

Aside from the fact that both protagonists were separately married at a time when divorce was only granted on proof of a matrimonial crime, the book became notorious for its explicit descriptions of sex, ​its use of then-unprintable four-letter words and a reference to anal sex, ​which was illegal at the time.

The book challenged establishment values and, although it had been published elsewhere in Europe in 1928, remained unpublished in the UK for 30 years following Lawrence’s death in 1930, as publishers were fearful of prosecution.

Penguin’s co-founder Allen Lane wanted to publish an unabridged cheap paperback version for three shillings and sixpence, the same price as 10 cigarettes, to make it affordable for the “young and the hoi polloi”.

The previous year had seen the enactment of the Obscene Publications Act 1959, which introduced a defence for publishers if they showed that a work was of literary merit and for the public good. The trial of Penguin Books was a test case of the new law.