draw on/upon sth
phrasal verbwithdrawverb[T]uk/drɔː/usdrew|drawn
tostartusing asupplyof something:
Americansarespendingmore than theyearn,drawingonsavingsandbuildingupdebtto do so.
He hassecuredaloanfor a newbuildingbydrawingupon theresourcesof twoexistingtenants.