A review of separation agreements will pave the way for them to become legally binding for the first time.
It follows a series of high-profile cases in which pre-nuptial agreements have been challenged in the courts.
Deals signed after marriage, known as post-nups, would also be protected by law if ministers agree to reform.
The change would give individuals the right to hold on to savings, homes or other assets if a relationship breaks down, without facing lengthy and expensive litigation.
Pre-nups have become increasingly common in Britain, especially among the wealthy, but at present they are not protected by legislation.
If challenged, it is up to the courts to decide on a case-by-case basis whether they should be honoured, which has led to a number of well-publicised legal battles.
Last year, the Supreme Court effectively gave its backing to such agreements in a landmark ruling which gave Katrin Radmacher, a German heiress, the right to withhold the vast majority of her £100 million fortune from her former husband.
“Post-nups,” though less common, are also recognized under the Matrimonial Property Act. (One recent, relatively high-profile example: Playboy Playmate Kendra Wilkinson wants her husband, mediocre football player Hank Baskett, to sign a post-nuptual agreement to protect the money she earned from her sex tape. It’s the most beautiful love story since Sid & Nancy!)