What is sedition?
Sedition is overt conduct that instils insurrection (unrest) or contempt in the general population against the monarch or his or her heirs, or the government or its functionaries.
While seditious conduct can take the any form, commonly, cases have been brought for giving speeches, and for writing, printing or distributing text or pictures. These tend to also be acts of libel, of making statements that are untrue and that have existential permanence.
Origins
Seditious libel became a legal concept through an Act of Parliament in 1275. The telling or publishing of "any false news or tales whereby discord or occasion of discord or slander may grow between the king and his people or the great men of the realm" became a crime tried by the King’s council in the Star Chamber (a court that sat at the Palace of Westminster).
In a 1606, the Case De Libellis Famosis, tried in the Star Chamber, developed the concept. Libel against a private person was ruled to be able to constitute a crime, if it could provoke revenge leading to a breach of the peace. Libel against the monarch or the government might also be a crime because "it concerns not only the breach of the peace, but also the scandal of government."
More importantly, although libel usually requires the statement made to be untrue, the Star Chamber ruled that the truth of a statement that is seditiously libellous was not a consideration under the common law. In other words, any criticism of the monarch or of the government could be seditious, even true ones.
The argument was as follows. An effective government must command the respect and allegiance of the people. Since any criticism undermines this respect and allegiance, any criticism must contribute towards disorder, however greatly. And true libel – publication of the truth – is more dangerous for the stability of the state than false libel, since false libel can be proved as untrue.
At a time when there was considerable dissent against the monarch and the government, suppression of criticism, especially when it was true, was important for keeping power. An accusation of seditious libel (even where the evidence was scant) allowed a general warrant to be issued, which in turn gave power to government officers to arrest any suspect and to search his or her home. An accusation therefore became a tool that allowed harassment of suspected dissenters and their families.
In public, the saying "the greater the truth the greater the libel” came into use.
Blasphemous libel
Seditious libel and blasphemous libel were often the same – criticising the monarch amounted to criticising God’s appointment of the King as ruler. The King held absolute power of government through his divine right (enacted into law by the Supremacy of the Crown Act 1534, which established him as head of the Church of England).
Blasphemous libel was abolished as a crime in the Criminal and Justice and Immigration Act 2008.
Abolishment of sedition
The last prosecution for sedition in the United Kingdom was in 1972. Three men were charged with seditious conspiracy for attempting to recruit people to fight in the Irish Republican Army. However, they received suspended sentences for offences against the Public Order Act.
The common law offences of sedition and seditious libel were abolished in the Coroners and Justice Act 2009. Sedition by someone who is not a UK citizen is still an offence under the Aliens Restriction (Amendment) Act 1919.