The Habeas Corpus Act passed by Parliament in 1679 guaranteed that a person detained by the authorities would have to be brought before a court of law so that the legality of the detention may be examined. In times of social unrest, Parliament had the power to suspend Habeas Corpus. William Pitt did this in May 1793 during the war with France. Parliamentary reformers such as Thomas Hardy and John Thelwall were imprisoned as a result of this action.
Habeas Corpus was also suspended in January 1817 after a missile had been thrown through the glass window of the Prince Regent's coach on the way to the opening of Parliament. Supporters of parliamentary reform were blamed for this act of violence and Lord Liverpool and his government rushed through Parliament the Gagging Acts. These measures banned meetings of over fifty people and instructed magistrates to arrest everyone suspected of spreading seditious libel.
The Gagging Acts severely hampered the campaign for parliamentary reform. However, as soon as Parliament decided to restore Habeas Corpus in March, 1818, there was an immediate revival in the demands for universal suffrage.