Venues in London which cancelled an anti-gay marriage conference have been accused of exhibiting the behaviour of ‘a fascist or Communist regime’, after meeting organiser Christian Concern said gay equality advocates were ‘right to be scared’ of them.

The Law Society and the Queen Elizabeth II Conference Centre in Westminster both cancelled a conference organised by the World Congress of Families and Christian Concern in May when they were alerted to its purpose of opposing equal marriage rights for gay couples.

Organisers were told ‘One Man. One Woman. Making the case for marriage, for the good of society’ could not go ahead at the Law Society and that their money would be refunded. The manager in question said it was not a step the organisation took “lightly”.

He said: “However, where an event does not fit within this company’s diversity policy, it is a step we must take.

“The nature of your event has recently been drawn to our attention, and it is contrary to our diversity policy, espousing as it does an ethos which is opposed to same sex marriage.”

The conference organisers then booked the Queen Elizabeth II Conference Centre in Westminster, which is owned by the government and which similarly cancelled the booking.

Christian Concern has suggested the cancellations came about because equal marriage advocates are afraid the religious arguments against homosexuality are convincing and will undo the gay “revolution”.

The group intends to sue both venues for breach of contract and make a claim in respect of discrimination under the Equality Act 2010, in relation to the beliefs held by Christian Concern concerning marriage.

Ann Widdecombe has now added her voice to the debate, saying the cancellation of the conference was designed to do “exactly what we would expect from a fascist or Communist regime but it has no place in modern Britain”.

She wrote in her Daily Express column: “The arguments in favour or against gay marriage are not important in this context. The issue is a simple one: freedom of speech.”

Although the government did not attempt to ban the conference from taking place elsewhere, and an alternative venue was found, Ms Widdecombe said it showed freedom of assembly for those who do not subscribe to the “prevailing orthodoxy” is in danger.

She said: “Parliament was assured, on the record, that homosexual equality measures would never result in curtailing the freedom to say that homosexual acts were wrong, yet now we have reached a stage where a conference aimed at nothing more than preserving the legal uniqueness of traditional marriage is regarded as unacceptable.

“The manipulation of public opinion through the curtailing of free speech is exactly what we would expect from a fascist or Communist regime but it has no place in modern Britain.”

At the £75-a-head conference, Brian Brown, President of the US National Organization for Marriage called for more money to be given to anti-gay marriage campaigns, arguing that “same-sex relationships” and “marriage” were mutually exclusive terms because a gay couple could not conceive children.

Don Feder of the World Congress of Families was reported to have told the audience gay sexual acts were always wrong. According to Christian Concern Phillip Blond, Director of Res Publica, argued that gender-neutral marriage “removes the right to marry from heterosexual people”.

After the conference, Andrea Minichiello Williams, CEO of Christian Concern, claimed the body was “never hateful”, and added: “Possibly, these desperate attempts by the homosexual lobby to silence anyone who wants to have a reasoned debate about marriage, society and sexual ethics betrays a deep insecurity.

“Maybe they are afraid that, that if people hear the arguments, they may change their minds. Maybe they are scared that their revolution will be exposed as unworkable and detrimental to the whole of society?

“They are right to be scared, because it is. And we must love them and point them to the hope that is in Jesus.”