LONDON — The paperback is not in the best condition.

Sotheby’s, which sold it at auction, notes that the spine is chipped, the pages are starting to come loose and an old paper clip has left a rust mark on the cover. It’s also full of pencil underlinings, with a separate note giving page references for the rude bits.

But this copy of “Lady Chatterley’s Lover,” by D.H. Lawrence, used in perhaps the most famous British obscenity trial of the past century, is now designated a cultural treasure in Britain. It has been banned by the government from leaving the country until at least August while a crowdfunding campaign races to match its auction price of 56,250 pounds (about $71,000).

“‘Lady Chatterley’s Lover’ was at the heart of the struggle for freedom of expression, in the courts and beyond,” Philippe Sands, the president of English PEN, the free-speech charity running the crowdfunding campaign, said in a statement. “This unique text belongs here, a symbol of the continuing struggle to protect the rights of writers and readers at home and abroad.”