Mislaying personal data may soon become a criminal offence.
The House of Lords has backed an amendment to the Criminal Justice and Immigration Bill, proposed by Liberal Democrat Lady Miller.
The amendment will criminalise anyone who "intentionally or recklessly discloses information" or "repeatedly and negligently" allows information to be disclosed in breach of the law.
The House of Commons must also back the amendment before it can become part of the Bill.
The change to the Bill follows a number of privacy blunders over the past six months that have seen government agencies and banks losing personal details of thousands of members of the public.
Last week Information Commissioner Richard Thomas revealed that he received reports of 94 security breaches during 2007 and urged businesses and the public sector to make data protection a key concern.