The Shawcross principle is an idea in the United Kingdom's Westminster system of government, whereby the Attorney-General is to be left to his or her own devices and judgments regarding whether or not to establish criminal proceedings.
[3] In a lengthy defence of his conduct regarding an illegal strike, Attorney General Hartley Shawcross cited hundreds of years of precedent as to the firm foundation of his actions.
[7] In 2004 in the context of the Tony Blair's invasion of Iraq, a whistleblower by the name of Katharine Gun risked prosecution under the Official Secrets Act.
Goldsmith sent a "Shawcross letter" to the foreign secretary, Jack Straw, who was responsible for GCHQ, advising him that HMG should decline to pursue Gun.
[8] The Shawcross Principle was the judicial doctrine that the ethics commissioner Mario Dion said Canadian Prime Minister Justin Trudeau breached in the Jody Wilson-Raybould - SNC Lavalin bribery and fraud prosecution case.