Couples considering living together should seriously consider a pre-cohabitation agreement, an expert family lawyer is warning.

MFG Solicitors partner Karen Reynolds said while it might not seem desperately romantic, such an agreement could save considerable heartbreak in the event of a future break up.

It is advice that many others have also given. She said: "Family lawyers are currently awaiting publication of the Government's proposals to enable cohabitants to make financial claims against each other if their relationship should break down."

It is expected that the consultation document will be issued this summer but it is unlikely that any Bill will be put before Parliament before 2008.

Ms Reynolds said: "As the law stands, if such a relationship ends then the non-owning cohabitant may find they become embroiled in complex and costly proceedings based upon land and trust law to even establish a financial interest in the home they may have shared for years.

"There have been suggestions that this will be particularly important for unmarried cohabitants that have children. However, provision already exists under Children Act 1989 to allow the parent with care to claim a lump sum or transfer of property to provide a home for the child.

"In big money cases this can lead to substantial awards. This applies even if the parents have never lived together, as was the case in 2003 when the Court of Appeal awarded a mother a lump sum of £1 million to buy a house and associated expenses. The mother was also awarded periodical payments of £70,000 per annum for the child.

"In another case in 2006, the Court of Appeal upheld the earlier High Court order requiring the father to set up a trust fund of £700,000 to purchase a home for the child and periodical payments of £60,000 per annum."

She said that in contrast to divorce cases, a lump sum awarded under the Children Act to buy a home for the child would revert to the paying parent when the child reaches majority. The periodical payments would also cease.