(1)This section applies if—
(a)the Crown Court has passed a sentence on a person in respect of an offence, and
(b)the person falls within subsection (2).
(2)A person falls within this subsection if—
(a)he receives a discounted sentence in consequence of his having offered in pursuance of a written agreement to give assistance to the prosecutor or investigator of an offence but he knowingly fails to any extent to give assistance in accordance with the agreement;
(b)he receives a discounted sentence in consequence of his having offered in pursuance of a written agreement to give assistance to the prosecutor or investigator of an offence and, having given the assistance in accordance with the agreement, in pursuance of another written agreement gives or offers to give further assistance;
(c)he receives a sentence which is not discounted but in pursuance of a written agreement he subsequently gives or offers to give assistance to the prosecutor or investigator of an offence.
(3)A specified prosecutor may at any time refer the case back to the court by which the sentence was passed if—
(a)the person is still serving his sentence, and
(b)the specified prosecutor thinks it is in the interests of justice to do so.
(4)A case so referred must, if possible, be heard by the judge who passed the sentence to which the referral relates.
(5)If the court is satisfied that a person who falls within subsection (2)(a) knowingly failed to give the assistance it may substitute for the sentence to which the referral relates such greater sentence (not exceeding that which it would have passed but for the agreement to give assistance) as it thinks appropriate.
(6)In a case of a person who falls within subsection (2)(b) or (c) the court may—
(a)take into account the extent and nature of the assistance given or offered;
(b)substitute for the sentence to which the referral relates such lesser sentence as it thinks appropriate.
(7)Any part of the sentence to which the referral relates which the person has already served must be taken into account in determining when a greater or lesser sentence imposed by subsection (5) or (6) has been served.
(8)A person in respect of whom a reference is made under this section and the specified prosecutor may with the leave of the Court of Appeal appeal to the Court of Appeal against the decision of the Crown Court.
(9)Section 33(3) of the Criminal Appeal Act 1968 (c. 19) (limitation on appeal from the criminal division of the Court of Appeal) does not prevent an appeal to the Supreme Court under this section.
(10)A discounted sentence is a sentence passed in pursuance of section 73 or subsection (6) above.
(11)References—
(a)to a written agreement are to an agreement made in writing with a specified prosecutor;
(b)to a specified prosecutor must be construed in accordance with section 71.
(12)In relation to any proceedings under this section, the Secretary of State may make an order containing provision corresponding to any provision in—
(a)the Criminal Appeal Act 1968 (subject to any specified modifications), or
(b)the Criminal Appeal (Northern Ireland) Act 1980 (c. 47) (subject to any specified modifications).
(13)A person does not fall within subsection (2) if—
(a)he was convicted of an offence for which the sentence is fixed by law, and
(b)he did not plead guilty to the offence for which he was sentenced.
(14)Section 174(1)(a) or 270 of the Criminal Justice Act 2003 (c. 44) (as the case may be) applies to a sentence substituted under subsection (5) above unless the court thinks that it is not in the public interest to disclose that the person falls within subsection (2)(a) above.
(15)Subsections (3) to (9) of section 73 apply for the purposes of this section as they apply for the purposes of that section and any reference in those subsections to subsection (2) of that section must be construed as a reference to subsection (6) of this section.