The Canadian military mission to combat and contain the Islamic State in Iraq continues to receive majority support from Canadians — but this support is beginning to soften and is increasingly divided across partisan divisions and other key faultlines.

This development should surprise no one; we saw the same pattern play out with the Afghanistan mission. An initial reaction of moral outrage triggered by the serial atrocities of IS — also known as ISIS or ISIL — will be tempered by a more hard-headed appraisal of the pros and cons of the mission as time goes on.

The question of extending the mission in duration and scope is far more controversial. Support for extending the mission has dropped over the past two weeks as the debate has heated up. On a scrupulously neutral question (which we have repeated) Canadians are evenly divided on whether to extend the mission.

There are very distinct groups — such as women, Quebeckers, visible minorities and non-Conservative supporters — who are clearly offside with an extension of the mission. Given the trajectory of support for extending the mission, and historical patterns of eroding support for past missions, it’s probably safe to say that we could see majority opposition to the mission extension in the near future.

The question of whether the mission should be expanded to include a ground combat role for the Canadian Forces is basically a non-starter with most Canadians and finds little favour with anyone other than Conservative supporters. The boundaries between combat activities and the Canadian Forces’ current role in Iraq is vague at present, and many experts believe that defeating IS would require ground combat. Nevertheless, it’s clear that most Canadians want no part of that.

How will all this play out politically in an election year? Hard to say. The Iraq campaign and the security file in general have given Mr. Harper a clear boost in the polls. On the need to contain and confront the Islamic State, he has enjoyed a rare moment of accord with Canadian majority opinion on a topic which sees a clear difference of opinion between the government and opposition.

Yet as support for the mission has softened, so too has Harper’s rise in the polls — now stalled and arguably falling backward. It seems unlikely at this point that this mission extension will provide much support to Mr. Harper’s quest for another mandate in October; by then, it could be a brake rather than a boon.

Tom Mulcair’s NDP has risen into a newly competitive position with a clear upward trend; this may be due to his clear opposition to the mission, or to his opposition to C-51, or both. Justin Trudeau has seen his poll position erode since the start of the Iraq mission, but his clear denouncement of the extension could end up putting him on the right side of public opinion as the debate continues.

Frank Graves is founder and president of EKOS Polling.

Methodology:

This study was conducted using High Definition Interactive Voice Response (HD-IVR™) technology, which allows respondents to enter their preferences by punching the keypad on their phone, rather than telling them to an operator. In an effort to reduce the coverage bias of landline only RDD, we created a dual landline/cell phone RDD sampling frame for this research. As a result, we are able to reach those with a landline and cell phone, as well as cell phone only households and landline only households.

The field dates for this survey are March 18-25, 2015. In total, a random sample of 4,942 Canadian adults aged 18 and over responded to the survey. The margin of error associated with the total sample is +/-1.4 percentage points, 19 times out of 20.

Please note that the margin of error increases when the results are sub-divided (i.e., error margins for sub-groups such as region, sex, age, education). All the data have been statistically weighted by age, gender, region, and educational attainment to ensure the sample’s composition reflects that of the actual population of Canada according to Census data.