Marriage became legal for same-sex couples in March 2014, but civil partnerships, generally seen as a substitute for marriage, remained an option as well.
Recent figures from the Office for National Statistics have shown exactly what the effect of same-sex marriage has been on the number of couples opting for civil partnerships.
Registrations for civil partnerships were cut almost in half following the legalisation of same-sex marriage. There were 1,683 such registrations in 2014, the year same sex marriages were introduced, but only 861 in 2015, a drop of 49%.
Compared to 2013, before same sex marriages had become legal in the UK, the difference is even more pronounced. Since then, the number of registrations for civil partnerships is down by 85%.
Interestingly, there have also been changes to the kinds of people who are registering for civil partnerships over the same time period.
For example, there has been a shift towards older people choosing to register for civil partnerships since marriage became an option for same-sex couples.
In 2013 the average age of a man entering a civil partnership was 40.8, and for a woman it was 37.9. In 2015, these figures had risen to 48.5 for men and 49.1 for women. While in 2013 just 19% of those entering civil partnerships were aged 50 or above, in 2015 couples over 50 accounted for 48% of new civil partnerships.
Men seem to have a greater tendency than women to continue to choose civil partnerships over marriage.
2015 saw the highest proportion of male civil partnerships since the year of their introduction in 2005.
Initially, men were more prevalent in the formation of civil partnerships but the split between men and women later evened out to fluctuate each side of the 50/50 mark. In 2015, however, men became decidedly the larger group of new civil partners and accounted for two thirds of all civil partnerships formed.
Women, on the other hand, more readily took up the opportunity to marry same-sex partners. Between the introduction of same-sex marriage in March 2014 and June of the following year, female couples accounted for the majority of marriages between partners of the same sex.
As civil partnerships are often seen as a substitute for marriage aimed at same sex couples, many have questioned whether this kind of union has a future now that such couples are able to simply get married.
Couples who were already in civil partnerships have the right to convert their existing legal union into a marriage, and many have chosen to do so. Furthermore, the data shows that couples are largely and increasingly choosing marriage over a civil partnership now they have the option, and there is little expectation that this trend will do anything but continue.
There are, however, opposite-sex couples campaigning for civil partnerships to be opened up to them, as currently these kinds of unions are only open to same-sex couples.
Some opposite-sex partner’s feel for various reasons, such as objections to the cultural and ideological baggage associated with marriage, that they would like access to an alternative that is more along the lines of civil partnerships.
If civil partnerships do continue to exist in years to come, this may be the purpose that they serve.
Kerry Smith is the head of family law at K J Smith Solicitors, a specialist family law firm who deal with a wide range of issues including divorce, domestic violence, civil partnerships and prenuptial agreements.