The Government has admitted mistakenly including a law that threatens to jail for life anyone who has called for the abolition of the monarchy on a list of recently repealed offences.
Section three of the Treason Felony Act 1848, which has not been used to prosecute anyone since 1879, was included on a list of 309 offences to be repealed in the year to May, published by the Ministry of Justice.
But in an embarrassing blunder, the Government department has admitted the offence was included on the list in error.
A Ministry of Justice spokeswoman said: "Section three of the Treason Felony Act 1848 has not been repealed. The Ministry of Justice has removed this publication and is reviewing its contents."
That means in theory it is still punishable by life imprisonment to "imagine" overthrowing the Crown or waging war against the Queen, as the wording of the Act describes.
The section of the Act was challenged in the High Court in 2001 by The Guardian newspaper, which claimed the Act violated article 10 of the European Convention on Human Rights, which guarantees the right to free speech.
The case was the first to be brought purely under the Human Rights Act, which at the time had been in force for just four months.
The challenge was launched after the paper's editor Alan Rusbridger was unable to gain official reassurance that a campaign calling for a referendum on the future of the monarchy would not lead to prosecutions under the Act.
Ultimately, five law lords in the House of Lords deemed the newspaper's actions to be unnecessary.
At the time, Lord Steyn said: "The part of section three of the 1848 Act which appears to criminalise the advocacy of republicanism is a relic of a bygone age, and does not fit into the fabric of our modern legal system."
Yesterday, it emerged "being an incorrigible rogue", under the Vagrancy Act 1824, had also been repealed.
A total of 327 criminal offences were also created in the year to May, a 12% increase compared with the previous 12 months.
:: In full, section three of the Treason Felony Act 1848 reads:
If any person whatsoever shall, within the United Kingdom or without, compass, imagine, invent, devise, or intend to deprive or depose our Most Gracious Lady the Queen, from the style, honour, or royal name of the imperial crown of the United Kingdom, or of any other of her Majesty's dominions and countries, or to levy war against her Majesty, within any part of the United Kingdom, in order by force or constraint to compel her to change her measures or counsels, or in order to put any force or constraint upon or in order to intimidate or overawe both Houses or either House of Parliament, or to move or stir any foreigner or stranger with force to invade the United Kingdom or any other of her Majesty's dominions or countries under the obeisance of her Majesty, and such compassings, imaginations, inventions, devices, or intentions, or any of them, shall express, utter, or declare, by publishing any printing or writing ... or by any overt act or deed, every person so offending shall be guilty of felony, and being convicted thereof shall be liable ... to be transported beyond the seas for the term of his or her natural life.