From early in 1793, judicial measures, some questionable procedurally and some seen to be over-severe, were used to repress reforming views. In July Vaughan successfully defended a Knutsford bookseller who had stocked works of Tom Paine.[15] Advising James Watt junior, then abroad, Vaughan took the view that he was safe from prosecution.[16] He was counsel, with John Gurney, for Thomas Briellat, convicted in December 1793 for using seditious language.[17][18] In making the defence case, Vaughan emphasised the ubiquity of the Association for Preserving Liberty and Property.[19]
Vaughan took part as junior counsel in the defence of the reformer Thomas Walker on trial in Lancaster for seditious conspiracy, with Thomas Erskine.[23][24] The trial began in April 1794, and Walker was acquitted, with the main prosecution witness discredited.[25]
Vaughan in May 1794 defended George Harley Vaughan, a schoolmaster who had circulated a handbill about the war and its effect on the poor, on a seditious libel charge in Leicester.[26][27][28] He was present with John Frost when John Horne Tooke's house was searched after his arrest in May, and visited him in the Tower of London.[29] Subsequently, however, he was examined by the Privy Council, where he fended off implications of misprison of treason. As a consequence he was denied access to Horne Tooke, for a period from June.[30] He has been considered the author of the pamphlet Cursory Strictures of 2 October 1794 on the handling of the treason trials by Sir James Eyre LCJ, as has William Godwin.[31] He was junior counsel also that month in the trial of Thomas Hardy,[32] and for the trial of Horne Tooke in November.[33] Pages were removed from the LCS minute book, and Vaughan has been considered likely to be the person who did that.[34] Of the group of defendants charged with Hardy and Tooke, Jeremiah Joyce chose Vaughan as counsel, rather than the team of Erskine and Vicary Gibbs.[35]
In January 1795 Vaughan was unsuccessful in the defence of James Montgomery at Doncaster Assizes.[36] In 1797 he and Samuel Romilly defended John Gale Jones at Warwick Assizes; Jones was convicted but not sentenced.[37]
Thomas Banks made a series of plaster busts of the radicals around Horne Tooke, and Vaughan was included.[38]
^Jenny Graham (2000). The Nation, the Law, and the King: Reform Politics in England, 1789–1799. Vol. 2. University Press of America. pp. 503–4. ISBN0-7618-1484-1.
^Jenny Graham (2000). The Nation, the Law, and the King: Reform Politics in England, 1789-1799. Vol. 2. University Press of America. p. 602 note 210. ISBN0-7618-1484-1.
^Wharam, Alan (1992). The Treason Trials, 1794. Leicester University Press. p. 123. ISBN0718514459.
^Jenny Graham (2000). The Nation, the Law, and the King: Reform Politics in England, 1789-1799. Vol. 2. University Press of America. p. 602. ISBN0-7618-1484-1.
^The City of Leicester: Parliamentary history, 1660-1835, in A History of the County of Leicester: Volume 4, the City of Leicester, ed. R A McKinley (London, 1958), pp. 110-152 http://www.british-history.ac.uk/vch/leics/vol4/pp110-152 [accessed 2 April 2015].
^Wharam, Alan (1992). The Treason Trials, 1794. Leicester University Press. pp. 93 and 127. ISBN0718514459.
^Jenny Graham (2000). The Nation, the Law, and the King: Reform Politics in England, 1789–1799. Vol. 2. University Press of America. pp. 615–6 and note 41. ISBN0-7618-1484-1.
^Wharam, Alan (1992). The Treason Trials, 1794. Leicester University Press. p. 133. ISBN0718514459.
^Wharam, Alan (1992). The Treason Trials, 1794. Leicester University Press. p. 142. ISBN0718514459.
^Wharam, Alan (1992). The Treason Trials, 1794. Leicester University Press. p. 194. ISBN0718514459.
^Jenny Graham (2000). The Nation, the Law, and the King: Reform Politics in England, 1789–1799. Vol. 2. University Press of America. p. 654. ISBN0-7618-1484-1.
^Jenny Graham (2000). The Nation, the Law, and the King: Reform Politics in England, 1789–1799. Vol. 2. University Press of America. pp. 761 note 59. ISBN0-7618-1484-1.
^Albert Goodwin (1979). The Friends of Liberty: The English Democratic Movement in the Age of the French Revolution. Hutchinson of London. p. 365. ISBN978-0-09-134170-1.