Archbishop of York Dr John Sentamu is being heavily criticised for opposing government plans to legalise same-sex civil marriage.
Both religious and secular campaigners for 'equal marriage' say that he is wrong to try to legislate against those who hold a different view to him.
Civil rights activist Peter Tatchell, who spoke at the Greenbelt Christian arts festival in 2010, says the Archbishop is insinuating that the government is behaving in a dictatorial manner over the issue, while actually trying to force his own personal view on others in the form of discrimination.
A change in the law would allow civic and faith bodies to be involved in same-sex marriages if they wish, but not force those like Dr Sentamu who do not. But the archbishop's own preference for a continued ban would stop others going ahead.
Mr Tatchell declared: "The Archbishop is unelected, whereas the government is democratically elected and a clear majority of the public support same-sex civil marriages."
Nearly two-thirds of the British public say the law on civil marriage should not discriminate.
A Populus poll, published in The Times newpaper in June 2009, found that 61 per cent of the public believe that: "Gay couples should have an equal right to get married, not just to have civil partnerships." Just 33 per cent disagreed.
Mr Tatchell continued: "It is not a loving Christian value to demand legal discrimination against gay couples and to treat them as inferior, second class citizens.
"The government is proposing to legalise same-sex marriages in register offices only. This will not affect churches. The Archbishop has no valid grounds for objecting to civil registrations that will ensure marriage equality for all couples.
"The vast majority of the British people, including many Christians, support the right of same-sex couples to get married. Dr Sentamu is intolerant and out of touch. His stance colludes with homophobia. It brings shame and dishonour to the Church of England.
"The Archbishop's insulting, disparaging attitude towards lesbian and gay people is evidenced by the way he dismisses loving same-sex civil partnerships as mere friendships.
"His demand ... is very similar to the arguments that were in the past used by the church to justify slavery, colonialism and the denial of votes to women," concluded Mr Tatchell.
The Equal Love campaign is seeking to overturn the twin legal bans on same-sex civil marriages and opposite-sex civil partnerships.
It played a major role in persuading the government to commit to the legalisation of same-sex civil marriages, and currently has an appeal against the twin bans under consideration by the European Court of Human Rights.
The campaign is backed by a range of Christian organisations, including LGCM and the thinktank Ekklesia. (www.equallove.org.uk)