Just as supporters of same-sex marriage are celebrating the U.S. Supreme Court ruling that struck down the federal Defense of Marriage Act law as unconstitutional, so the campaign for the right of equal marriage (to include same-sex couples) is reaching its critical phase in the United Kingdom.

And just as the progressive streams of Judaism have been vocal in their support for gay marriage in the U.S. , the campaign for equal marriage in the U.K. has been led by Liberal Judaism (the British equivalent of American Reform, representing just under 10% of Jews in the U.K.), together with the Quakers and the Unitarian Church. The U.K. campaign is set to succeed despite the opposition encountered over some 15 years from the majority of those who declare that they speak for British Jews.

It could be as early as the end of 2013 that equal marriage will be enacted into the law of England and Wales, following the approval of the Marriage (Same Sex) Bill by both chambers of Parliament. Members of the House of Commons voted 400 in favor and 175 against, and the House of Lords backed the proposal by a similar margin. The Lords are expected to complete a line-by-line examination of the measure by the end of the summer.

The Marriage (Same Sex) Bill permits those religious streams who so desire to solemnize marriages between two men or two women in, for example synagogues or other religious buildings. Liberal Judaism’s Council (on which each of its 39 congregations is represented) has already indicated its wish to proceed with this. The same legislation protects the right of individual institutions which refuse to adopt equal marriage policies, and prohibits same sex marriages being conducted under the auspices of the Church of England.

For Liberal Judaism, equal marriage is both a matter of justice and a question of religious freedom. Liberal Judaism has always considered itself welcoming to, and affirming of, everyone who has sought to make use of its services, although it was not until 1991 that Liberal Judaism published its pamphlet, "Where We Stand on Homosexuality?" Primarily motivated by the intolerant backlash that had followed the AIDS epidemic, the pamphlet rejected prejudice and discrimination, and affirmed the idea that "the appropriate context for the expression of human sexuality is a lasting relationship of mutual love and faithfulness between two persons."

Eleven years later, the Rabbinic Conference of Liberal Judaism approved "the recognition of Same-Sex Partnerships between two Jews by appropriate Jewish ritual and support[ed] those [rabbis] who officiate at such ceremonies." It accepted that, for many Jewish same-sex couples, the natural and appropriate symbols for such ceremonies would be those of the Jewish wedding service, and that the traditional terminology of holiness and sanctification rightly reflected the way in which many same-sex couples understand and conduct their relationships. It further gave permission for those to take place in a synagogue where the rabbinic and lay leadership of the local congregation agreed.

In the wake of England and Wales’ 2004 Civil Partnership Act, Liberal Judaism published an explanatory pamphlet, "Lesbian and Gay Jews and Same-Sex Relationships" as part of a series exploring how Liberal Judaism puts faith into practice. More significantly, and probably as the first synagogal movement in the world to do so, Liberal Judaism published "Brit Ahavah (Covenant of Love): A Liturgy for the Service of Commitment for Same-Sex Couples."

Two years ago, Liberal Judaism formally resolved to update our liturgy and practice in accord with equal marriage provisions. It did so because it sees its mission as making Judaism relevant to the modern Jew and assisting Jews and others to live as part of, and not apart from, the world as it is today. Conscious of the Biblical ethic that each person is created in the Divine image and aware that Jewish tradition is itself a product of the environment in which it was forged and practised, Liberal Judaism wishes to provide a ceremony which sanctifies and celebrates a belief in loving, monogamous relationships. Further - and in accord with traditional Jewish teaching that marriage is a contractual arrangement by the partners concerned - Liberal Jewish understanding can see no moral, logical or practical reason why the possibility of marriage should not be extended to same-sex couples.

It is more than a decade ago that the Netherlands became the first jurisdiction in the world to legalize equal marriage. The "equal marriage" bloc has increased by a third in the last year alone, and now encompasses many countries in Europe and Latin America. A similar pattern is reflected at the state level in the United States with Massachusetts having led the way in 2004; now 12 U.S. states have passed legislation permitting equal marriage.

This dramatic change in legal and social mores will lead to an increasing demand for Jewish communities to make provision for equal marriage under the chuppah, and a number of Jews and their institutions will surely innovate and experiment with liturgy and other practices. Anecdotal evidence from Britain’s Liberal synagogues after the introduction of civil partnerships suggests that Liberal rabbis will see only a modest demand for equal marriage ceremonies in the U.K. But perhaps, just as importantly, Judaism – on this occasion through its Liberal stream – will have made another contribution to the well-being of the societies in which it thrives.

Rabbi Danny Rich is the Chief Executive of Liberal Judaism in the U.K.