Interveners at the Supreme Court of Canada

By Sancho McCann · , edited:

Third par­ties sub­mit am­i­cus briefs (“friend-of-the-court” briefs) in al­most every U.S. Supreme Court case. 781 were sub­mit­ted in the term span­ning 2014–2015—an av­er­age of 12 per case—and 147 in the mar­riage equal­i­ty case alone.,

Canada’s clos­est ana­logue to the U.S.’s am­i­ci are called “in­ter­ven­ers”. From 2000–2008, in­ter­ven­ers par­tic­i­pat­ed in only about 50% of cas­es at the Supreme Court of Canada, av­er­ag­ing 2.4 in­ter­ven­ers per case. This was de­spite the court grant­i­ng 94% of the re­quests to in­ter­vene.

How has this changed since then? In the pe­ri­od from 2010–2016, in­ter­ven­ers par­tic­i­pat­ed in ap­peals more fre­quent­ly than they did from 2000–2008, but still at nowhere near the rate of am­i­ci at the U.S. Supreme Court.

To give a sense of who these in­ter­ven­ers are, here are the par­ties that in­ter­vened at least five times over this sev­en-year pe­ri­od.

Attorneys gen­er­al dom­i­nate the top of the list, as they al­ways have. Together, they ac­count­ed for 25% of all in­ter­ven­tions from 2010–2016. This is a no­tice­able de­crease com­pared to the num­bers from 10 and 20 years ago. In the pe­ri­od from 2000–2008, at­tor­neys gen­er­al ac­count­ed for 37% of all in­ter­ven­tions. In the pe­ri­od from 1997–1999, they ac­count­ed for 42%. Non-gov­ern­ment in­ter­ven­ers like pub­lic in­ter­est groups, trade as­so­ci­a­tions, and in­di­vid­u­als are par­tic­i­pat­ing more now than ever be­fore.

In the midst of this gen­er­al in­crease in in­ter­ven­tions, one cat­e­go­ry of cas­es con­tin­ues to lag be­hind. Most of the case­load at the Supreme Court of Canada con­sists of dis­cre­tionary ap­peals: the ap­pel­lant re­quests that their ap­peal be heard, and the court de­cides whether they will hear the case. But, about 20–25% of the case­load at the Supreme Court of Canada con­sists of ap­peals that are heard “as of right”—au­to­mat­i­cal­ly. As-of-right ap­peals gen­er­al­ly in­volve in­dictable crim­i­nal offenses where one of the judges at the low­er court dis­agreed with their court’s de­ci­sion. In 2016, only two of the four­teen ap­peals in that cat­e­go­ry at­tract­ed any in­ter­ven­ers.

I can think of two rea­sons why these cas­es are get­ting less help from in­ter­ven­ers.

For a case to make it onto the court’s dis­cre­tionary dock­et, it must pass through a filter. The court se­lects cas­es that in­volve “a ques­tion of pub­lic im­por­tance or […] an im­por­tant is­sue of law”. As-of-right ap­peals side­step this filter. This could lead to these cas­es just not be­ing as in­ter­est­ing to out­side par­ties.

Another ex­pla­na­tion could be that the ap­pel­lants in these cas­es (of­ten, crim­i­nal de­fen­dants) don’t have the same abil­i­ty to wran­gle out­side help for their po­si­tion.


The Supreme Court of Canada is get­ting more in­put from third par­ty in­ter­ven­ers than ever be­fore. This is po­ten­tial­ly a good thing, but that de­pends on which the­o­ry re­gard­ing the role of in­ter­ven­ers is true.

The “Amicus Machine” in the U.S. was built over a pe­ri­od of about 15-20 years, large­ly undi­rect­ed, and not nec­es­sar­i­ly best de­signed to fill its os­ten­si­ble role.

As in­ter­ven­tions be­come more fre­quent at the Supreme Court of Canada, we (or rather, the jus­tices) have the op­por­tu­ni­ty to di­rect how this prac­tice grows. In par­tic­u­lar, we should be on the out­look for po­ten­tial dis­par­i­ties in ac­cess to jus­tice that come from the par­ties’ differing ac­cess to in­ter­ven­ers.