So when there's a perceived advantage to be pressed, leverage it posthaste.
We are contacting some consultants to see who will accept the scope of work and will process an agreement posthaste.
He begged the commandant general to send more, posthaste.
British Dictionary definitions for posthaste
posthaste
/ˈpəʊstˈheɪst/
adverb
1.
with great haste; as fast as possible
noun
2.
(archaic) great haste
Word Origin and History for posthaste
adv.
1590s, from a noun (1530s) meaning "great speed," usually said to be from "post haste" instruction formerly written on letters (attested from 1530s), from post (adv.) + haste (n.). The verb post "to ride or travel with great speed" is recorded from 1550s.
posthaste in Culture
posthaste [(pohst-hayst)]
Immediately, with great speed: “Get the flood warning to the media posthaste.”