(not possible) on such short notice
Fixed expression used with a negative sentence to mean that something cannot be done because the request or demand came too suddenly. Often used when someone is put on the spot.
I can't answer right away if you ask me so suddenly.
I'm not prepared when you tell me on such short notice.
A fixed expression combining the adverb 急に (suddenly) with the passive form of 言う (to say) and the particle ても (even if). The literal meaning is 'even if (I) am told suddenly', which has become a set phrase for expressing that something is impossible on short notice.