Mishcon de Reya has launched what is thought to be the first insurance policy in the UK to provide cover for legal costs in divorce proceedings should one party challenge a previously agreed prenuptial agreement.

The law firm has teamed up with legal expenses insurer ARAG and independent broker Lansdowne Partners to offer its clients Protect Pre-Nup.

Clients will pay an annual fee for the policy, which will be underwritten by ARAG, with Mishcons carrying out yearly risk assessments of the specified prenup.

The launch follows an ongoing consultation by the Law Commission looking at whether prenuptial agreements should become fully binding rather than subject to court approval.

There has been growing pressure for more certainty on prenups in the wake of the Radmacher case, which last year saw the Supreme Court back the enforceability of prenuptial agreements for the first time. It backed German heiress Katrin Radmacher (pictured), said to be worth £100m, in her dispute with her ex-husband Nicolas Granatino, reducing his award from £5.8m 
to around £1m.

Mishcons head of family Sandra Davis said: "Although couples can enter into prenuptial agreements, whether or not they are upheld is subject to the court's approval. We wanted to address this uncertainty and have therefore created this insurance policy which provides cover to help meet legal costs should a challenge to a prenuptial agreement arise.

She added: "Following the inevitable cuts to legal aid for families, this may well be the first step towards a before-the-event insurance option for married couples."