When David Cameron backed the legalisation of same-sex marriage in 2013, he said it was a simple matter of equality. Quite right too. But now, a year later, he has rejected the principle of equality by refusing to allow opposite-sex couples to have a civil partnership.
His government announced yesterday that it is maintaining the current ban on male-female civil partnerships. What happened to Cameron's much boasted commitment to equal rights for all? Surely, in a democracy we should all be equal before the law?
Since the legalisation of same-sex civil marriage, for the first time in British history, gay and lesbian couples have a legal advantage over straight ones. Same-sex couples have two options: civil marriage and civil partnership. In contrast, opposite-sex couples have only one option: marriage. This is profoundly unjust and unfair.
How did we get into this bizarre mess?
In 2012, at my request, the government's public consultation on legalising same-sex marriage included a question on whether civil partnerships should be retained and opened to heterosexual couples. Over 200,000 people participated in the consultation. A whopping 61% supported extending civil partnerships to opposite-sex couples. Only 24% opposed.
This was not the result the government wanted, so David Cameron ordered a new public consultation earlier this year on the future of civil partnerships. This time only just over 10,000 people responded. The churches mobilised to oppose civil partnerships for opposite-sex couples, in the absurd belief - apparently shared by David Cameron - that legalising them would undermine marriage. How exactly?
Both civil marriages and civil partnerships embody the same core values of love, commitment, loyalty and stability. Why does it matter if a straight couple choose a civil partnership? How does their choice undermine the marriages of the others and the authority of an institution that still enjoys majority support?
Civil partnerships may be a different institution from marriage but they are, in most respects, marriage-like. So why maintain the ban on female-male civil partnerships?
This year's public consultation got the result the government wanted: 76% opposed civil partnerships for heterosexual couples; 22% supported them.
Majority opinion has been allowed to veto equality and human rights. That's wrong.
As a basic democratic and human rights principle, everyone should be equal in law. To deny opposite-sex couples the right to have a civil partnership is discrimination and discrimination is wrong. It cannot be justified, no matter how many or how few opposite-sex couples may want a civil partnership.
Many male-female couples (and same-sex ones) don't like the sexist, homophobic history of marriage. They are turned off by the antiquated language of husband and wife. They'd prefer a civil partnership; finding it more egalitarian and modern. They don't want to be married.
Marriage should therefore not be the only option. Couples should not be forced to marry to get legal recognition and rights. They should have the alternative option of a civil partnership.
For their security and their mutual rights and responsibilities, it is better that currently unmarried opposite-sex couples have a civil partnership, rather than merely live together and have nothing; especially where children are involved.
The UK should adopt the popular Dutch system of opening civil partnerships to both same-sex and opposite-sex couples. A majority of Dutch civil partnerships are now between heterosexual men and women. The same is likely to happen if UK civil partnerships were made available to couples of the opposite-sex. Based on the experience in the Netherlands, around 10-15% of British male-female couples would seek a civil partnership if it was available.
Indeed, the government's 2014 consultation on the future of civil partnerships found a potentially even higher up-take. Of currently unmarried heterosexuals, 63% said they would choose marriage and 20% indicated they would prefer a civil partnership, if it was available.
Legalising same-sex marriage was the recognition that lesbian, gay, bisexual and transgender (LGBT) people are of equal worth and have the right to equal treatment in law. The same principle of equality applies in the case of civil partnerships. Heterosexual couples should be able to have a civil partnership.
My human rights campaigning is based on the principle of equality for all. I can't accept LGBT human rights at the expense of equal rights for straight people. For me, selective and partial equality is unthinkable. That's why I back heterosexual equality in civil partnership law.
On a separate point: I am delighted the government has announced that same-sex couples in civil partnerships will be able to convert them into marriages, if they wish, from December this year. But why the long delay until then? This is nine months after the first same-sex marriages and 18 months after the legislation was agreed by parliament.
For more information about Peter Tatchell's human rights campaigns and to make a donation: PeterTatchellFoundation.org