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Spies and others who leak classified information could face tougher sentences under a proposed overhaul of the four Official Secrets Acts.

The Law Commission's proposals come after it was asked by the Cabinet Office to examine how effective the acts are in the 21st century.

Proposals include replacing three of the acts, from 1911, 1920 and 1939, with a single Espionage Act.

It is the first time in 100 years the acts have been fully reviewed.

The acts aim to protect government information from unauthorised disclosure of classified information, which is protected because it could harm national security or damage international relations.

The Official Secrets Act 1911 is still the main source of legal protection in the UK against espionage, more than a century after it was first drawn up.

The review found it should now be expanded to include offences committed by people other than British subjects.

Image copyright Getty Images Image caption Whistleblower Edward Snowden who worked with the National Surveillance Agency, fled the US after leaking classified information

The Law Commission - an independent body set up to reform the law - also proposed an increase in maximum sentences.

Currently, most offenders prosecuted under the Official Secrets Act 1989 receive a maximum of two years' imprisonment.

The consultation points out that it is the same penalty for information disclosed which damages national security as for a data breach by a National Lottery worker.

It also argues that in the "digital age", the "ability to cause damage to the national interest" and the risk of doing so has increased.

Proposals from the Law Commission include:

Clarifying the scope of espionage type offences and those related to making unauthorised disclosures

Increased maximum sentences to reflect the seriousness of some conduct

New measures to ensure sites such as embassies are protected if necessary

Making clear that leaking sensitive information is a criminal offence whether at home or abroad

Simplifying and modernising the language to remove terms like "code words" and "enemy"

Law Commissioner, Prof David Ormerod QC, said: ""We have made a number of provisional conclusions as to how the legislation could be improved that we believe will enhance the protection that is currently afforded to official information."

Speaking to the Daily Telegraph, Prof Ormerod said the review was a "once in a century opportunity".

The review is currently at consultation stage- with members of the public invited to respond until 3 April.