Pursuant to section 5(1) of the Divorce Act, the jurisdiction to hear and determine a variation proceeding vests in the court of a province wherein either former spouse is ordinarily resident at the commencement of the variation proceeding, or in a court whose jurisdiction is accepted by the former spouses,3provided that any such court must fall within the definition of "court" in section 2(1) of the Divorce Act. To avoid the exercise of competing or conflicting jurisdictions by courts of competent jurisdiction in different provinces, sections 5(2) and 5(3) of the Divorce Act provide that where variation proceedings are brought on different days before two courts of competent jurisdiction, the first in time prevails unless it is discontinued within 30 days of its commencement, and where the variation proceedings are brought on the same day, the Federal Court - Trial Division has exclusive jurisdiction to hear and determine the variation proceedings.
Where a variation proceeding with respect to child support is joined with an application for a custody order that is opposed, and the child is most substantially connected with another province, a court with jurisdiction over the variation proceeding under section 5 of the Divorce Act may transfer the variation proceeding to a court in that other province.4In
that event, the court to which the variation proceeding has been transferred has exclusive jurisdiction to hear and determine the proceeding by virtue of section 6(4).
No Canadian court has jurisdiction under the Divorce Act to vary a spousal or child support order granted in a foreign divorce proceeding. The definitions of "child support order" and "spousal support order" in section 2(1) of the Divorce Act clearly demonstrate that variation orders under section 17 of the Divorce Act are available only when the original order was granted pursuant to sections 15.1 (child support) or 15.2 (spousal support) of the Divorce Act. Jurisdiction to vary foreign support orders can only be derived from provincial legislation respecting the enforcement and variation of support orders.5
 Tatlock v. Lays,  A.J. No. 962...