Catholic bishops in England and Wales said they strongly oppose a bill to redefine marriage to include same-sex couples.
Archbishop Vincent Nichols of Westminster and Archbishop Peter Smith of Southwark -- the president and vice president of the Bishops' Conference of England and Wales -- criticized moves to legalize gay marriage as "shambolic" and urged lawmakers to vote against a forthcoming bill.
"It is not too late to stop this bill," they said in a statement issued Tuesday, hours after Culture Secretary Maria Miller revealed the contents of the proposed legislation in the House of Commons.
"The meaning of marriage matters," the archbishops said. "The government has chosen to ignore the views of over 600,000 people who signed a petition calling for the current definition of marriage to stay, and we are told legislation to change the definition of marriage will now come to Parliament.
"We strongly oppose such a bill," they said. "Furthermore, the process by which this has happened can only be described as shambolic."
Scotland's bishops echoed the opposition.
The English archbishops argued that the government had circumvented all the normal legislative pathways. These include, they said, a failure to insert such controversial proposals in election manifestos, to announce them the latest legislative program, and to hold up the legislation to public scrutiny through "Green" and "White" Papers.
The archbishops said there had been "a constant shifting of policy" right up to the present moment.
"We urge everyone who cares about upholding the meaning of marriage in civil law to make their views known to their Members of Parliament clearly, calmly and forcefully, and without impugning the motives of others," the archbishops said, adding that all the political parties should allow there members to vote with their consciences.
In remarks to the House of Commons, Miller confirmed Prime Minister David Cameron's reported intentions to allow churches to "opt in" to same-sex marriage legislation, but she said that this would not include either the Church of England or the Church of Wales, national Anglican churches that fiercely objected to the proposals.
She said the government was treating them differently because it "recognizes and protects the unique and established nature of these churches."
Miller promised a "quadruple lock" to guarantee religious freedom for all the churches. This includes four steps, including a pledge on the face of the bill that no religious organization or minister can be compelled to marry same-sex couples.
Religious organizations other than the Anglican churches will be able to "opt in," however, if their hierarchy or governing body permits it, she said.
Miller also promised to amend the 2010 Equality Act to protect churches. Brushing aside concerns that the legislation could be challenged in the European Court of Human Rights, she said: "With appropriate legislative drafting the chance of a legislative challenge through domestic or European courts is negligible."
Legislation to legalize same-sex marriage will be formally presented to Parliament in the New Year with the aim of becoming law by 2014. The government has been saying it would push for same-sex marriage in civil offices and hotels, and including churches dramatically widens the scope of the legislation.
The proposals to redefine marriage have been opposed by the Catholic, Anglican and the Evangelical churches and by Jewish, Sikh and Muslim leaders.
The proposal to allow same-sex couples to marry in churches had earlier met with dismay from some Catholic bishops.
Bishop Philip Egan of Portsmouth said in a statement posted Monday on his diocesan website that the prime minister was "luring the people of England away from their common Christian values and Christian patrimony, and forcing upon us a brave new world, artificially engineered."
"If the prime minister proceeds with these intentions, he will pervert authentic family values, with catastrophic consequences for the well-being and behavior of future generations," he said. "He will smother the traditional Christian ethos of our society and strangle the religious freedom of the Catholic church in Britain to conduct its mission."
Bishop Mark Davies of Shrewsbury said Christians were approaching a time when they had to give "clear and courageous witness to the truth about marriage."
"It is a tragic moment for British society with serious implications for religious freedom," he said in a text message Monday to Catholic News Service. "However, as Christians we must see the moment to give our witness for the common good of society and for the sake of generations to come."