Hi there,
Maybe I can be of assistance, because this sounds a little distinctive and yes...
Given that you're all focusing on the same issue, I would expect that you've been given something to differentiate your presentations - slightly different topics, perhaps? If that's the case, consider focusing on the subtle differences between topics. If you can, use the key words to draw out those distinctions, to help you find potential evidence and examples that makes your view on the issue unique.
Canvas the likely examples and arguments that groups before you will raise (make a list) and keep brainstorming. Because you're going last, you'll need to find an interesting and novel way into the issue. What ideas are the other groups unlikely to touch on? If you expect them to rely on similar arguments, consider those they are likely to avoid and move away from any conventional arguments. Finding different players/interested groups should help you to consider alternate viewpoints. Also, it might be that many of the groups are likely to reach the same conclusion if the issue lends itself to one side more than the other. If so, can you formulate strong arguments that would allow you to make the case for the opposite side? The other way to keep your audience entertained is to consider the anecdotes you use - storytelling and narrative will work to your advantage here.
You could also consider doing something that would set your group (and you) apart in terms of format. Rather than doing a Q&A, you might be better off adopting something satirical or humorous. Would doing something like a mock government briefing work? Or you could consider staging a fake meeting of an organisation, where people do mini soapbox arguments. Especially if you expect everything that precedes you to be serious, adopting a more light-heated approach will keep your audience (and assessor) engaged.
Hope that helps!