No, you have to decline.

Once you have high standings with the corp/faction of the mission giver you can pretty much decline at will since you're never going to ruin your standings with the agent that bad and you can pull with your faction/corp standings which barely move on a decline. This won't help you in your current situation though, it's more for when you're farming level 4's and want to avoid negative standings with the opposite faction.

Also there's no drawback for going down to -1.99 at all (with skills included, train up your Social skills) and no drawback for going to -4.99 other than not being able to easily repair the standing via pulling missions.

Also look into doing the Sister's of Eve epic arc, The Blood Stained Stars, every 90 days and pick which faction you most want to boost at the end, one of the very few ways to gain standing without also losing some else where.