Earlier in 2017, the now-ousted former Sauber boss Monisha Kaltenborn negotiated a customer engine deal with the struggling Japanese manufacturer for 2018.
But Frederic Vasseur is now in charge at the Swiss team, triggering speculation the deal is off.
Indeed, the rumble in the Silverstone paddock is that the Sauber-Honda arrangement only ever got to the point of a letter of intent and official announcement rather than a concrete contract.
Honda F1 director Mashashi Yamamoto said at Silverstone: “We are ready to equip Sauber with power units.
“I built up a lot with Monisha Kaltenborn and we would be happy to have Sauber. Honda has no objections to the originally agreed deal.”