Please do not use either of these expressions if you are asking someone to do something that they might not be willing to do. Both are extremely offensive.
If you are that person's boss, then possibly they will put up with such abrasive language. But even then it is better to phrase your request more politely.
Less offensive ways of phrasing your request could inlcude:
- Please could you...
- I would be grateful if you ...
It would be very helpful if you could...
and so forth.
Many years ago I worked as a close assistant to an extremely senior government official in my country. If he really wanted me to do something important, and do it now, he would say "One thing you might do is...". He got it, and got it now.
All the above is very much a matter of British English understatement. Maybe they use rougher language elsewhere. But if English is not your native language I suggest you might start mildly and become more direct if that seems to get people going more effectively.