Gay equality campaigners have condemned Pope Benedict’s latest attack on same-sex marriage.

The Pope made the comments yesterday while visiting Fatima, Portugal’s most holy site.

He called abortion and same-sex marriage “some of today’s most insidious and dangerous threats to the common good” and urged for protection of the “family based on the indissoluble marriage between a man and a woman”.

The Pontiff is due to visit the UK later this year.

Peter Tatchell, who has been leading criticism of the state-funded visit, called him an “arch-homophobe”.

He told PinkNews.co.uk: “It is utter madness for the Pope to equate same-sex marriage with terrorism, war, poverty and climate destruction.

“He is not only losing his sense of moral priority but also his capacity for rational thought.”

Mr Tatchell said a Protest the Pope campaign was planning a series of small protests in the coming months, culminating in a large event during the visit.

Stonewall also criticised the remarks, with director of public affairs Derek Munn telling the Daily Telegraph: “Some might say that it’s dangerous and insidious for the Pope to spend so much time publicly belittling gay, lesbian and bisexual people.”

George Broadhead, secretary of gay humanist charity Pink Triangle Trust, added: “These repeated attacks on gay rights, and in particular the right to marriage, amount to a paranoid obsession about what the Pope clearly perceives as an intrinsic moral evil.

“Given that the stance of all three main UK political parties is supportive of gay rights, are their leaders going to have the guts to condemn this overt hostility and will the new coalition government think twice about welcoming this ghastly bigot to the UK next [sic] September?”

The Vatican’s official stance on homosexuality is that it is a “deviation” and the act of homosexual sex is a sin.

The Pope has become more vocal on the subject of homosexuality in recent years.

He recently criticised gay rights measures contained in Britain’s Equality Act. He said measures designed to ensure churches were not discriminating when hiring staff were against “natural law”.

Following his attack, the government backed down on pushing the measures through.

In an end-of year address in 2008, he said that the existence of gay people threatens humanity as much as the destruction of the rainforests does and that “blurring” genders through acceptance of transgender people would kill off the human race.

He has also attacked the use of condoms to tackle HIV, saying they may make the problem worse.