A letter signed by more than 50 public figures says that the Pope should not be given the "honour" of a state visit to the UK.
The letter, published today in the Guardian newspaper, argues that while the Pope is free to visit his British followers, his teachings on sexual issues mean he should not be accorded a state visit.
It charges that the Pope has opposed the use of condoms, denied abortion to vulnerable women, opposed gay and lesbian rights and failed to address cases of alleged child abuse.
The letter adds: "The state of which the Pope is head has also resisted signing many major human rights treaties and has formed its own treaties ('concordats') with many states which negatively affect the human rights of citizens of those states.
"In any case, we reject the masquerading of the Holy See as a state and the pope as a head of state as merely a convenient fiction to amplify the international influence of the Vatican.
Signatories included gay broadcaster Stephen Fry, atheist campaigner Richard Dawkins, novelist Terry Pratchett and writer Johann Hari.
The Pope will arrive in the UK tomorrow for a four-day visit. He is expected to meet the Queen in Scotland and hold an open-air mass in Birmingham.
Today, prime minister David Cameron appeared in a video message welcoming him to the UK.
Mr Cameron, who will have a private meeting with the Pope on Saturday, said that the UK would give him a "very warm welcome".
However, there has been concern that tickets for the open-air mass, which will include a beatification of Cardinal Newman, are not selling as well as expected.
The mass was originally going to be held at a larger venue and 10,000 of the 60,000 £25 tickets have not been sold.
The Catholic Church is expected to pay £10 million towards the visit. The state is to pay another £10 million, although this does not include the cost of security.
Earlier this month, a poll of 2,005 adults by Theology thinktank Theos found that 77 per cent said the taxpayer should not fork out for part of the trip's cost.
Hundreds of people are to join a march in London on Saturday against the Pope's teachings and the state-funded visit.
Stephen Fry and Richard Dawkins say Pope should not be given 'honour' of state visit
6:15 PM
picture