R (Ewing) v Davis [2007] EWHC 1730 (Admin)
There has never been any legal requirement that a private prosecutor has to demonstrate that it is in the public interest that he should bring a prosecution for an offence against the provision of a public general Act of Parliament. However, under the Prosecution of Offences Act 1985, s 6(2) the DPP and CPS have the power to take over a private prosecution and, under s 23, to discontinue it. Moreover, if the criminal proceedings brought by a private prosecutor are thought to be vexatious, the Attorney General can apply, under the Supreme Court Act 1981, s 42 for a criminal proceedings order.