Behn v. Moulton Contracting Ltd. 2013 SCC 26 holds:
 In Toronto (City) v. C.U.P.E., Local 79, 2003 SCC 63,  3 S.C.R. 77, Arbour J. wrote for the majority of this Court that the doctrine of abuse of process has its roots in a judge's inherent and residual discretion to prevent abuse of the court's process: para. 35; see also P. M. Perell, "A Survey of Abuse of Process", in T. L. Archibald and R. S. Echlin, eds.,Annual Review of Civil Litigation 2007 (2007), 243. Abuse of process was described in R. v. Power,  1 S.C.R. 601, at p. 616, as the bringing of proceedings that are "unfair to the point that they are contrary to the interest of justice", and in R. v. Conway,  1 S.C.R. 1659, at p. 1667, as "oppressive treatment." In addition to proceedings that are oppressive or vexatious and that violate the principles of justice, McLachlin J. (as she then was) said in her dissent in R. v. Scott,  3 S.C.R. 979, at p. 1007, that the doctrine of abuse of process evokes the "public interest in a fair and just trial process and the proper administration of justice". Arbour J. observed in C.U.P.E. that the doctrine is not limited to criminal law, but applies in a variety of legal contexts: para. 36.
 The doctrine of abuse of process is characterized by its flexibility. Unlike the concepts of res judicata and issue estoppel, abuse of process is unencumbered by specific requirements. In Canam Enterprises Inc. v. Coles (2000), 51 O.R. (3d) 481 (C.A.), Goudge J.A., who was dissenting, but whose reasons this Court subsequently approved (2002 SCC 63,  3 S.C.R. 307), stated at paras. 55-56 that the doctrine of abuse of process
engages the inherent power of the court to prevent the misuse of its procedure, in a way that would be manifestly unfair to a party to the litigation before it or would in some other way bring the administration of justice into disrepute. It is a flexible doctrine unencumbered by the specific requirements of concepts such as issue estoppel. See House of Spring Gardens Ltd. v. Waite,  3 W.L.R. 347 [C.A.], at p. 358.
One circumstance in which abuse of process has been applied is where the litigation before the court is found to be in essence an attempt to relitigate a claim which the court has already determined. See Solomon v. Smith, supra. It is on that basis that Nordheimer J. found that this third party claim ought to be terminated as an abuse of process. [Emphasis added.]
 As can be seen from the case law, the administration of justice and fairness are at the heart of the doctrine of abuse of process. In Canam Enterprises and in C.U.P.E., the doctrine was used to preclude relitigation of an issue in circumstances in which the requirements for issue estoppel were not met. But it is not limited to preventing relitigation. For example, in Blencoe v. British Columbia (Human Rights Commission), 2000 SCC 44,  2 S.C.R. 307, the Court held that an unreasonable delay that causes serious prejudice could amount to an abuse of process: paras. 101-21. The doctrine of abuse of process is flexible, and it exists to ensure that the administration of justice is not brought into disrepute.