By the end of 2019, different-sex couples in the UK will be able to enter into civil partnerships. This option is already available to same-sex couples, and the Equal Civil Partnerships Campaign has been fighting to have it extended to everyone. It’s taken a Supreme Court case as well as years of political campaigning to succeed. Civil partnerships bring largely the same legal rights and duties as marriages, meaning all couples will soon have the choice of two almost-identical statuses with different names.

Legislators in Alabama, USA, recently voted to remove marriage licenses, replacing them with marriage “certificates”; if the law is in enacted, you’ll need a certificate to get married. But what’s the difference? Some Alabama judges have refused to sign marriage licenses since the US Supreme Court ruling in Obergefell v. Hodges required states to recognise same-sex marriage. Rep. Wes Allen, an Alabama judge who opposes same-sex marriage, believes that signing a marriage license is tantamount to endorsing a marriage. Since he doesn’t endorse same-sex marriage, he won’t sign a license for a same-sex couple.

The new marriage certificates will still need to be signed by judges. But they would simply record that the couple has filed the necessary legal documents. A judge’s signature would confirm that a legal process has been followed. It would not mean that the judge approves the marriage as such.

Judges like Allen don’t want to be complicit in the state’s endorsement of same-sex marriage. And they’re right that when the state recognises marriage, it also endorses the institution. The state’s recognition of marriage does other things too: it defines what marriage is, it controls access to the institution, and it provides a bundle of rights and duties to the marrying couple. Approval, though, is central.

What is the state approving when it recognises marriage? It’s not just committed relationships or family stability, because these can exist outside of marriage, too. It’s approving committed relationships that seek sanctification or certification specifically as marriages.

The name “marriage” is important, because it designates a traditional institution rich with meaning, history, and, for many, religious significance. For some people the traditional meanings of marriage are a vital part of its value. They may wish the term was reserved for relationships that fit this mould. This is the view of many of those who oppose same-sex marriage, particularly on religious grounds.

For others, the traditional connotations of marriage are the problem. They see marriage as a patriarchal institution, associated with sexism and homophobia. The campaign for equal civil partnerships was largely a demand for an institution that protects families without requiring couples to buy into a traditional institution with patriarchal resonance.

The UK, in common with many other countries, first legislated to allow same-sex couples to register their relationships as civil partnerships but not marriages. The name mattered. It allowed the state to extend legal rights to lesbian and gay couples without clashing with traditional understandings of marriage. Same-sex marriage, for traditionalists, would be an illegitimate redefinition of the institution.

That move was strategic but ultimately inadequate – it didn’t secure equal recognition for same-sex couples. Denying same-sex couples the right to be married by the state is to deny them full equal status. And so the inequality was rectified in 2013, when the law was changed to give same-sex couples the right to choose between civil partnership, or marriage.

At the time, the then prime minister David Cameron resisted calls to make civil partnerships an option for different-sex couples. “I am a marriage man,” he said in parliament. “I am a great supporter of marriage. I want to promote marriage, defend marriage, encourage marriage, and the great thing about last night’s vote is that two gay people who love each other will now be able to get married. That is an important advance. We should be promoting marriage, rather than looking at any other way of weakening it.”

Cameron was right to recognise the power of the term, but wrong to insist on its enduring dominance. Insisting that relationships can only be recognised by the state if they use the term marriage satisfies neither traditionalists, nor progressives.

The use of “marriage” satisfies traditionalists only if they are allowed to control access to the institution and exclude same-sex couples, something that is unjust in a free and equal society. On the other hand, progressives are happy with the recognition of same-sex relationships, but requiring everyone to use the term “marriage” doesn’t meet the needs of those with feminist or atheist objections to the institution’s patriarchal and religious history.

Giving all couples the option to choose between registering their relationship as a civil partnership or a marriage is a great improvement on a regime that recognises only marriage. In my book Against Marriage: An Egalitarian Defence of the Marriage-Free State, I argue that it does not, however, go far enough, because the state should not recognise marriage at all.

In my ideal world, which I call the marriage-free state, marriage would not be banned. People would be free to have religious or secular ceremonies to solemnise and celebrate their relationships, and they would be free to call those relationships “marriage”. But marriage would have no legal status.

The marriage-free state has two main benefits. First, it removes the inequalities (legal, financial, and symbolic) between married and unmarried people and their children. Second, it means that the state no longer has to get involved in the fraught and controversial issue of determining what “marriage” means. It doesn’t have to rule between the progressives and the traditionalists about the true meaning of that resonant institution. It doesn’t have to endorse or approve of one way of understanding relationships.

It does take a stance on equality before the law by providing default regulations that apply to everyone engaged in particular relationship practices. In doing so, the marriage-free state provides a set of rights and duties that protect the vulnerable and apply equally to all relationships.

So, is the Alabama vote to remove marriage licenses to be commended? The vote might seem to be in line with the principles of the marriage-free state. Its stated aim is to remove the requirement for judges to do something – sign a “license” – that can be interpreted as endorsing marriage. And the marriage-free state refrains from endorsing married life as better than other family and relationship forms.

But there is a crucial problem. The Alabama decision arose not because some judges objected to endorsing marriage at all. They were happy to endorse different-sex marriages, but they did not want to endorse same-sex ones. This means those judges wanted to discriminate against lesbian and gay people. As Rep. Neil Rafferty said, the vote was “born out of prejudice”.

It might be tempting to think that it doesn’t matter what motivates a law; what matters is that the law is just. If the move from marriage licenses to marriage certificates allows same-sex couples to get married on the same terms as different-sex couples, what’s the problem?

In some cases, motivation may not matter. But this is not one of those cases. The fight for equal rights regardless of sexuality is far from over. People in the LGBT+ community still face serious prejudice and barriers to their equality. So the Alabama vote is inconsistent with the principles of the marriage-free state insofar as it gives credence to the discriminatory instincts of public officials.

Of course, the move to recognise same-sex marriage in the USA, the UK, and many other countries has played an important role in countering some of that prejudice. It has shifted public opinion towards greater acceptance of same-sex relationships. And it would be wrong to end the state recognition of marriage, including the affirmation that recognition gives, just when lesbian and gay people get access to it.

But the use of “marriage” has also provided a mechanism for the state to publicly affirm and indeed legalise homophobia. And although permitting same-sex marriage and different-sex civil partnership are significant steps towards equality and acceptance, these ideals will only be achieved in a marriage-free state.

Clare Chambers is Reader in Political Philosophy and Fellow of Jesus College, Cambridge. She is the author of Against Marriage: An Egalitarian Defence of the Marriage-Free State and Sex, Culture, and Justice: The Limits of Choice.

This article is part of the ​New Statesman's Agora series.