As one of his many objections to gay marriage, Lord Tebbitt recently argued it presents a nightmarish task for legislators. Not so much a can of worms as a ‘nest of snakes’. Fears include the possibility of changing every law in England and Wales with the words ‘husband’ or ‘wife’ and the need to redefine concepts of adultery and consummation of marriage.

Yet if we take our lead from the realities of LGBT relationships and seek common sense solutions, this can be a relatively simple legislative process.

Lord Tebbitt and other critics are quite right to suggest a great many laws use the word husband or wife. Many also use “spouse” and since 2004 “civil partner”. But there is no reason that same sex marriage should create a problem for the legal usage of these words.

Ask anyone in a civil partnership how they introduce their partner and the words “wife” and “husband” top the list. My bet is lesbian, gay, bisexual and transgender people who have a civil marriage will use exactly the same words. This is hardly surprising when people who want to get married are choosing to enter a deeply traditional institution.

It would be wrongheaded to attempt to create a non-discriminatory alternative name when LGBT communities are using the ones their parents and grandparents used. The new legislation simply needs to rule that the word “wife” now refers to any married woman, regardless of her spouse’s gender. The same goes for husbands.

With this definition extended to all previous laws, rights of property and inheritance pose no problems. Rules of social security, pensions and benefits too will simply be extended to all married couples, gay and straight.

The problem with adultery

The Conservative peer’s Telegraph article was on much surer ground when it highlighted issues in the definition of adultery, which is:

“Sexual intercourse taking place voluntarily between a married person and a person of the opposite sex, where the other person is not their spouse, whilst the marriage is still in existence. It is still adultery even if the parties to the marriage are already separated and the adultery was not the cause of the separation. Actual sexual intercourse must take place and that adultery can only take place between persons of the opposite sex and does not include same sex sexual relations.”

Under this definition a married gay man could have sex with as many male partners as he liked without his husband being able to get a divorce on grounds of adultery. Not a great fit with “forsaking all others.”

There are two ways to tackle this. We could have separate definitions for heterosexual and homosexual couples. But how would you treat a couple where one is straight the other bi, or one transgender one gay? This is where the worms start to crawl out of the can.

Instead the definition of adultery could be changed for all married couples. In doing so we have an opportunity to make the law a truer reflection of the values and beliefs of the society we live in. The current definition makes a rather heavy-handed point of ruling out same sex sexual relations as grounds for adultery. Legislators have considered this necessary, because there have been many cases of marriages breaking down because of homosexual affairs over the years. But shouldn’t this be grounds for adultery?

As a heterosexual married woman I doubt I’d be alone in wanting to divorce my husband if he had sex with a man. What if your supposedly straight spouse has a long drawn out affair with someone of the same gender? Surely people should have the right to apply for divorce in these circumstances, and that divorce should come with all the speed and certainty afforded a person whose spouse has been unfaithful with someone of the opposite sex.

A new definition of adultery would be welcome.

Consummation and annulments

The legal understanding of consummation of marriage also presents a problem. Legal theory considers consummation to involve sexual intercourse between one man and one woman involving penetration. Clearly this concept would not be appropriate for all LGBT relationships.

While agreeing it’s a tricky problem, I would argue that this is not an essential issue. In a legal context the issue of consummation is only important because non-consummation of marriage amounts to probable grounds for annulment. However annulments are not the instant get-out-of-marriage-free-cards of popular legend.

Marriages can be void or voidable. Void marriages are those that are legally regarded as not having taken place. Examples include if someone turns out to be under-age, or committing bigamy. A marriage which is never consummated is not void, merely voidable. It is fully recognised in law until a divorce decree absolute, or a decree of annulment. Other examples of voidable marriage include the presence of venereal disease and when a woman is pregnant by another at the time of the wedding.

The only real benefit of annulment over divorce is that voidable marriages can be annulled within a year of the marriage taking place. With divorce you have to wait twelve months. At the cost of this convenience annulment is more complicated and costly than divorce.

In practice annulments are now extremely rare and it is much more common for people to wait. With the exception of clients for whom money is no object, I think most family lawyers would recommend this way forward.

Legal rights for LGBT parents

Parental rights are a much thornier issue. Right now any LGBT couples who have children face fearsome legal problems; from who can be listed as a parent on the birth certificate, to lack of protection for surrogacy arrangements.

Technology and healthcare now enable gay people to have children, but the law has not kept pace. Whether conservative (with a small c) society likes it or not, many LGBT couples are choosing to have children. These families deserve proper protection and the law needs serious review. But this must be dealt with separately to gay marriage legislation. Some couples can and will choose to have children outside marriage and the law needs to be able to cope with that.

The awkward legacy of civil partnership legislation

Perhaps one of the reasons that some of those who oppose gay marriage overestimate its legal difficulties is that civil partnerships were born in a very messy piece of law-making.

Just one example is the fact that the House of Lords’ Bill did not amend tax legislation. This meant the separate Finance Act 2005 had to be passed to allow the Treasury to amend tax law. Additional complications came from the Lords’ lack of power to interfere with the Treasury, so more legislation was needed on top.

On the last day of the Civil Partnership Bill debate Jacqui Smith MP said “we have used civil marriage as the template for creating a completely new legal relationship…..our view was that, unless there was an objective justification for a difference in the approaches take to civil marriage and civil partnership, no difference should exist….it is not marriage, but it is, in many ways….akin to marriage”.

As such the Civil Partnership Act became basically a copy and paste job to mirror the rights of spouses. This was serious progress for equality, yet the decision to create something like marriage, which was not exactly marriage, was a clear policy decision to pacify the religious right. The inevitably awkward compromises that followed are a direct result of the decision to build this half-way house.

At last opening civil marriage up provides an opportunity for legal clarity and may even allow us to right some of the unnecessary quirks in our current system.

When deciding whether or not legal changes are necessary it’s worth remembering the purpose of law. It is there to serve people and to protect communities. In the last few decades acceptance of the equal rights of people of all sexual orientations has come thick and fast with each passing year. It’s time both the language and letter of the law caught up. Like every new piece of legislation enabling gay people to marry will require a certain amount of legislative work, but no more than average. Given that politicians in England and Wales passed 3,506 new laws in 2010 alone I think we can cope with one more in 2012.

Lisa Burton-Durham is a Chartered Legal Executive in family law at Mayo Wynne Baxter www.mayowynnebaxter.co.uk. You can add your views to her firm’s survey on gay marriage.