More couples in the UK are signing a pre-nuptial agreement than ever before, according to a new study.

Prenuptial agreements - or 'prenups' – are legal agreements signed before marriage that stipulate how assets should be divided in the event of a divorce.

Commonly perceived as the preserve of the super rich, the Savanta ComRes poll for the Marriage Foundation found that they are surprisingly common.

In the survey of 2,000 adults who were or are married, one in five answered 'yes' when asked if they had used a prenuptial agreement or knew someone who had.

According to the Marriage Foundation, just 1.5% of married couples in the 1970s had a prenup.

Employment was a key factor in the decision, with 44% of those in higher managerial, administrative or professional employment saying they had signed a prenup or knew someone who had.

This was far higher than the 18% of mid-level managers, skilled and semi-skilled workers.

The study also found that those who took part in a marriage preparation class were more likely to sign a prenup (64%) than those who had talked to a vicar (8%), and those who did no marriage preparation at all (4%).

Harry Benson, the Marriage Foundation's Research Director, said he was surprised by the popularity of prenups.

"At the levels suggested by the data, they are no longer a legal curiosity or quirk associated with the mega-rich and famous but appear to be becoming an integral part of getting married for large numbers of couples," he said.

"While signing a prenup does not appear to increase the chances of a divorce, our study suggests it is associated with lower levels of commitment with more couples drifting or sliding into marriage.

"This raises a question about why the lower level of commitment is not seen in higher break-up or divorce rates."