1. As soon as possible. (and you can suggest a specific deadline) Ex. As soon as possible and preferably before Friday. 2. Since the deadline is soon approaching, please provide your/the *^*^*^*^ so we can also meet our target of delivering the *^*^*^ in a timely manner and no less than three weeks prior to it having to be given to the specialist.

1. How to say "at your earliest convenience" but in a more demanding way? "at your earliest convenience" - is already polite business speak for, "we want it soon". Perhaps even stronger might be to mention consequences? Preferably in terms of importance to them. If they are delay-sensitive: Later than ... would risk/cause/necessitate rescheduling work. 2. How to remind gently about Client's obligations? ("Kind reminder" does not sound really good to my ear in this case). This is in line with the stated obligations (.. in the agreement). This is consistent with the stated obligations. This is consistent with the agreed obligations. or as an add-on to some part ....., as is consistent with the agreed obligations. , BTW: ... or my hands are tied. (Not tied up) :) See what ideas you get from others.

At the earliest opportunity? This means when you have a chance, whether or not it's convenient for you.