The phrase "as a single issue" is correct and usable in written English.
You can use it when discussing a topic or concern that is being considered in isolation, without reference to other related issues.
Example: "The committee decided to address the budget concerns as a single issue to ensure focused discussion."
Alternatives: "as an isolated matter" or "as a standalone issue".
"Given that people in the UK tend to see the Greens as a single issue party, that means they find it harder to attract support".
So worried are locals that one woman, Sandra Allison, is standing as a single issue Independent under the Save Hartlepool Hospital banner.
At 8.15am, Labour's Andy Burnham gives a speech in Manchester warning that the referendum should not be seen as a single issue protest vote.
Not that she wants to be seen as a "single issue" chair: she insists that promoting women in science is "an important strand in the group's thinking", not just her own.
But it is also one which means people often dismiss it as a single issue party, unlikely to become a force in Westminster politics.
The separately-traded companies would form the second-largest steel maker in China under the deal, which would rename the firms Hebei and be traded as a single issue of the parent, state-owned company.
In all, 49% of articles coded each complaint as pertaining to a single issue, while 51% coded a complaint as raising multiple issues.
The party, wrongly in my view, has failed to make the case for PR for the past decade out of a fear that it is perceived as only having a single issue.
But people would inevitably see it as being about a single issue.
While it was, initially for me, at least, the defining question that most potential voters asked, many "pundits" and organizational actors appeared to treat any mention of it as making one a "single issue" candidate.
For Sanders, big money corrupting politics is the problem that prevents the solution of other problems, making inequality not so much a single issue as a meta-issue.
