Salman Rushdie and other prominent authors have urged China to free 40 jailed writers, saying it would embarrass Beijing if they were still in jail during the Olympics.
The writers sent the letter to Chinese President Hu Jintao on Monday calling for the release of all detained writers and journalists prior to the Games in August next year.
"There are 40 of our colleagues in Chinese prisons who shouldn't be in prison," Rushdie said in a statement released to the press to publicise the letter.
"It will be an embarrassment for China if even one of them is still in prison when the Games begin next August. There's only one good number: zero."
The letter was part of a campaign launched by PEN, an international group of authors supporting freedom of expression, to press China to free detained writers, PEN said in a statement.
Margaret Atwood, the celebrated Canadian author and PEN vice president, said China was jeopardising the success of the Olympics by jailing writers.
"Let's hope that China does not ruin the international reception of its Olympic Games by keeping 40 writers in prison simply because they've exercised their right to freedom of expression," she said.
Rushdie is best known for his novel "The Satanic Verses," which forced him to go into hiding for a decade after then Iranian supreme leader Aytatollah Ruhollah Khomeini issued a death sentence against him for the book.
Atwood, 68, is a prolific novelist, poet and literary critic. Both authors have won Britain's prestigious Man Booker Prize.
The PEN letter contained names of the 40 Chinese writers and journalists detained, it said, "for exercising their right to speak and write freely, as guaranteed under Chinese and international law."
On Monday, media freedom watchdog Reporters Without Borders described China as "the biggest jail in the world for journalists."
It said that about 33 journalists and 49 cyber-dissidents are currently in prison in China.
China's communist rulers deny jailing writers and journalists for expressing their opinions, a right which they say is guaranteed by the country's constitution.
Beijing also says that it has lifted restrictions on foreign journalists to travel and conduct interviews ahead of the 2008 Olympics.