Case In Point
Divisional Court Reinforces Tradition of Judicial Deference to Ontario’s Labour Relations Board
Date: February 9, 2026
In the recent decision of United Association of Canada v. Labourers’ International Union of North America, Local 1059, the Ontario Superior Court of Justice (Divisional Court) dismissed an application for judicial review of a decision of the Ontario Labour Relations Board (OLRB), which involved a construction industry work assignment dispute.
This decision reinforces the Divisional Court’s longstanding tradition of affording a high degree of deference to the OLRB in labour relations matters due to its considerable specialization and expertise, and of affording the OLRB a particular degree of deference in construction labour relations matters, an area of particular expertise.
The decision also affirms that legislation created for the purpose of identifying the skills required for compulsory regulated trades will not override the factors the OLRB has relied upon for decades in work assignment disputes.
Background
A jurisdictional dispute arose in respect of work being performed at the Bruce “A” site of the Bruce Nuclear Power Development. The work involved the dismantling and removal of the plumbing of an old water-based fire suppression system, and the installation of a new water-based fire protection system.
E.S. Fox Limited (E.S. Fox) assigned the dismantling and removal work to members of the United Association of Canada, et. al. (UA), and subcontracted the installation work to Troy Life & Fire Safety Ltd. (Troy). Troy assigned the installation work to members of the UA.
The Labourers’ International Union of North America, Local 1059 and the Labourers’ International Union of North America, Ontario Provincial District Council (LIUNA) filed a jurisdictional dispute under section 99 of Ontario’s Labour Relations Act, 1995 against the UA disputing its jurisdiction to perform the dismantling and removal work, and the installation work.
OLRB Decision
The OLRB affirmed E.S. Fox’s work assignment of the dismantling work to members of the UA; however, it overturned Troy’s work assignment of the installation work to members of the UA, and found it was in LIUNA’s jurisdiction.
The OLRB noted that it has relied for decades on six factors in work assignment disputes: collective agreements; trade agreements between competing unions; employer practice; area practice; skill and ability; and economy and efficiency.
In arguments relating to “skill and ability,” the UA and Troy raised the Building Opportunities in the Skilled Trades Act (BOSTA), asserting that its provisions and regulations set out the tasks that are part of the trade of “sprinkler fitters,” and provide that only certified sprinkler fitters can safely perform the work in dispute.
The OLRB found that BOSTA should not be relied on to determine competing work jurisdiction issues, noting that it had long resisted the application of “apprenticeship and qualification legislation” to such disputes.
The OLRB found no evidence that the disputed work fell within the exclusive jurisdiction of the UA, and “significantly more” evidence that LIUNA’s members had performed installation work in the geographic area. The OLRB also found that the “area practice” factor, which it typically weighed most heavily, strongly favoured LIUNA with respect to the installation portion of the disputed work.
The UA and Troy applied to the OLRB for reconsideration of its original decision arguing primarily that the OLRB erred when it held that BOSTA ought not to be relied on to determine competing work jurisdiction issues. The OLRB rejected this argument and dismissed the application for reconsideration.
Divisional Court Decision
The single issue on judicial review was whether the OLRB’s failure to consider BOSTA rendered its decisions dealing with the jurisdictional dispute between the UA and LIUNA unreasonable.
The Court declined to intervene in the OLRB decision for the following reasons:
- Courts have “a long-standing jurisprudential commitment to affording labour relations decision makers the highest degree of deference.”
- The OLRB is “a highly specialized tribunal with considerable expertise, placing it in an elevated position to interpret its home statute.”
- Because construction labour relations is an area of “particular expertise”, it is afforded “particular judicial deference”.
- BOSTA is irrelevant in a jurisdictional dispute because:
- Its purpose is to identify the skills required for compulsory regulated trades.
- The OLRB has consistently determined that such legislation should not be relied on in a jurisdictional dispute regarding a work assignment.
- It does not override the established factors the OLRB considers in a work assignment dispute.
- The OLRB decisions “bear the requisite level of intelligibility, transparency and justification” and demonstrates “a coherent and rational connection between the relevant facts, the outcome…and the reasoning process that led the [OLRB] to that outcome.”
Key Takeaways
The decision of the Divisional Court in United Association of Canada v. Labourers’ International Union of North America, Local 1059, reinforces the longstanding tradition of affording a high degree of judicial deference to the OLRB in labour relations matters, and a particular degree of judicial deference in construction labour relations matters.
The decision also reinforces that legislation created for the purpose of identifying the skills required for compulsory regulated trades will not be relied on by the OLRB in a jurisdictional dispute regarding a work assignment. Rather, the OLRB will continue to consider the factors it has relied on for decades in work assignment disputes.
Hicks Morley’s Construction Practice Group acts for employers in both the unionized and non-unionized sectors of the construction industry and has deep understanding of the unique labour rules and practices construction employers face. Contact a member of our team for assistance with your matter.
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