A provision to make same-sex marriages illegal in the Church of England and Church in Wales has done little to assuage opponents of a change to the law.
The plans were outlined in the House of Commons today by Culture Secretary Maria Miller.
Other religious organisations would be able to "opt in" to offering same-sex weddings to gay couples, she said.
However, it will be unlawful for religious organisations or their ministers to wed same-sex couples unless their respective governing bodies have opted in.
Changes will also be made to equality laws to ensure that discrimination claims are not brought against clergy or religious leaders who refuse to perform same-sex marriage ceremonies.
Ms Miller said the provision making it illegal for the Church of England and Church in Wales to marry same-sex couples "recognises and protects the unique and established nature of those Churches".
She said the Church of England could change its view in the future and "we can consider the appropriate action to be taken".
The ban on the two Churches has upset the Archbishop of Wales, Dr Barry Morgan, who said the provision "curtails our freedom of choice and seems to close the door on even the possibility of doing so in the future without a change in law".
However, Sir Tony Baldry, who speaks for the Church of England in Parliament, said: "For the Church of England, the uniqueness of marriage is that it does embody the distinctiveness of men and women.
"So removing from the definition of marriage this complementarity is to lose any social institution where sexual difference is explicitly acknowledged."
Other Christians are angry that the Government is pressing ahead with the redefinition of marriage despite widespread opposition.
Catholic leaders accused the Government of choosing to "ignore" the more than 600,000 people who signed a petition defending the traditional definition of marriage.
In a joint statement, Archbishop Vincent Nichols and Archbishop Peter Smith said: "The process by which this has happened can only be described as shambolic.
"There was no electoral mandate in any manifesto; no mention in the Queen's speech; no serious or thorough consultation through a Green or White paper, and a constant shifting of policy before even the government response to the consultation was published today.
"We urge everyone who cares about upholding the meaning of marriage in civil law to make their views known to their MPs clearly, calmly and forcefully, and without impugning the motives of others. We urge all parties to ensure their members have a free vote. It is not too late to stop this Bill."
The head of the Christian Institute and Coalition for Marriage, Colin Hart, said that the Government's decision to push ahead with changes to the law were "disgraceful and undemocratic".
"All those who have signed the petition which the Government has now chosen to ignore deserve to be told why their name on a petition, which includes their address and signature, has been airbrushed out, while completely anonymous internet questionnaires have been counted – is this because a majority of MPs think that the Government should only proceed with their plans if they are supported by a majority of the respondents to the consultation?" he said.
Mr Hart raised serious questions about the manner in which the Government conducted its consultation.
In addition to anonymous submissions, some of the roughly 228,000 responses were accepted from non-UK residents despite concerns that pro-gay groups in the US had campaigned to get people to submit responses in favour.
Mr Hart continued: "There were serious flaws with the consultation, not only was it loaded in favour of ripping up the centuries-old definition of marriage, but it lacked even the most basic of safeguards to check the identity of those taking part."
David Burrowes MP said: "It makes the consultation a sham in terms of justifying this on the back of numerical support, given that 500,000 people were ignored and they have accepted all-comers from around the globe."
"The Government doesn't have a mandate to proceed and the consultation raises more doubts and questions about the public support for going forward."