at sb’s earliest convenience: 请某人尽快……,得便请尽早……
例如:I'm quite willing to discuss the matter at your earliest convenience.(我很愿意在你方便时,尽早与你讨论这一问题。)
I wonder if it would be possible for us to meet at your earliest convenience and discuss the matter in a little more detail.(如果方便的话,我们能否尽早和您见面,讨论一下这件事的细节。)