The attorney general has published advisory notes to help prevent people committing contempt of court by commenting on social media.

Guidelines warn that comment on a particular case needs to comply with the Contempt of Court Act 1981 and are designed to help inform the public about the legal pitfalls of commenting in a way that could be seen as prejudicial to a case.

The widespread use of social media has increased the risk that trials are prejudiced. So far this year the attorney general has issued 10 media advisories, the most ever issued by his office.

The notes had previously been issued only to print and broadcast media outlets on a ‘not for publication’ basis in cases including the murder of Tia Sharp, Sgt Danny Nightingale’s court martial and the arrest of Christopher Jefferies.

Dominic Grieve QC said: ‘Blogs and social media sites like Twitter and Facebook mean that individuals can now reach thousands of people with a single tweet or post. This is an exciting prospect, but it can pose certain challenges to the criminal justice system.’

‘In days gone by, it was only the mainstream media that had the opportunity to bring information relating to a court case to such a large group of people that it could put a court case at risk. That is no longer the case, and is why I have decided to publish the advisories that I have previously only issued to the media,’ said Grieve.

Grieve denied the notes are about telling people what they can or cannot talk about on social media, but said they are designed to help ‘facilitate commentary in a lawful way’.

‘I hope that by making this information available to the public at large, we can help stop people from inadvertently breaking the law, and make sure that cases are tried on the evidence, not what people have found online,’ he said.

Grieve added that the policy change will also bring more openness to the government’s dealings with the media so that both sides can be accountable to the public for what they do and say.

The notes have been published on the Attorney General’s Office section of the website and through the attorney’s twitter feed, @AGO_UK.