3. c. 3) is an Act of the Parliament of England which laid down rules of evidence and procedure in high treason trials.

By the 1680s even the notoriously severe Judge Jeffreys was prepared to admit that it was "hard" that the accused in a treason trial had no right to counsel.

[5] Today most of the Act has been repealed, but the three-year time limit still survives (see below), and of course, the rights to be represented and to have a copy of the indictment (now free of charge) still exist in other legislation.

The three-year time limit described above – and the original exception to it – are still on the law books today, and are contained in sections 5 and 6 of the Act.

[7]) When in 2000 a British newspaper suggested that James Hewitt be prosecuted under the Treason Act 1351 for an alleged affair with Diana, Princess of Wales,[8] it was pointed out that the mooted evidence fell outside the time limit.