I've dealt with this exact issue a few times as a project manager, and the key is framing your pushback around facts and options rather than complaints. Start by acknowledging the goal positively to show you're on board, then lay out the realities with specific details like the usual timeline and current constraints. For example, in an email, you could say something like, 'I'm excited about this project and appreciate the urgency, but based on past similar efforts that took six weeks, our current two-week deadline would require us to skip the 72-hour compliance review, which isn't feasible.' That way, you're highlighting tradeoffs without negativity.
In a live meeting, build on that by asking questions to engage them, like, 'If we adjust the scope to focus on the top three deliverables, could we extend to four weeks?' I once proposed a phased approach where we delivered a minimum viable product in two weeks and iterated from there, which leadership loved because it showed initiative. If I had to do it over, I'd always prepare a quick one-pager with timelines and risks to make my points visual and undeniable. It worked well in my last role, turning a potential conflict into a collaborative discussion.
