Polite alternatives to "as soon as possible"

I’ve found myself writing the phrase “as soon as possible” just too often. Sometimes I wonder if it sounds a little rude. How can I convey the same meaning in a more polite way but without losing sense of urgency?

Solution 1:

You could try at your earliest convenience, but there is a risk that somebody unfamiliar with idioms might take it as 'when convenient to yourself' (which is actually at your convenience).

Solution 2:

An alternative I see in business emails is:

As soon as you get a chance.

I like it because it implies sensitivity for the other person's schedule yet conveys the urgency of the matter.